Zowie S2 Review

S2 Mouse Intro

In this review, I'll be examining whether the S2 has any significant updates beyond the coating, alongside a thorough comparison with various other Zowie mice. The S2 Black and S1 Black now introduce Zowie's latest shape in their classic black matte finish, which might appeal to some users. Initially, the S Series was only part of their Divina line, featuring a glossy coating and available solely in blue or pink. Zowie's latest offering, the S Series, has certainly evolved.

The review will skip over the software and lighting aspects, adhering to Zowie's typical no-nonsense style. Equipped with Huano switches for the main buttons, the Zowie S2 features one of Pixart's best optical sensors, the PWM3360. It’s a medium-sized ambidextrous gaming mouse, but only has side buttons on the left side.

Specifications

Mouse Dimensions Overview

The recent Endgame Gear XM1, along with several other Zowie mice, is included in this table that features their dimensions. The term "Front height" refers to the space between the main buttons and the base. Measurements made with a ruler show one decimal, while those taken with a caliper have two decimals.

Build Durability

No accidental clicks happen even when the mouse is slammed down. There's no creaking or flexing of the shell when lateral pressure is applied. Shaking or tapping the mouse results in no rattle, showcasing the overall build quality as very solid.

Button Performance

The blue (dot) Huano switches used for the main buttons are rated for 10M clicks, although the exact rating of these specific switches is unknown. They are tactile and satisfying to press, providing a great feel. With minimal pre-travel and little post-travel, the main buttons of the S2 rank among the best clicks found on Zowie mice to date. Easy to press yet responsive, they really enhance the gaming experience.

The rating of the Red (dot) Huano switches used for the side buttons is unknown. They sit perfectly in size, striking a balance between the larger EC series side buttons and the smaller FK side buttons. The back button features little pre-travel and average post-travel, while the front button has very little pre-travel and post-travel, resulting in enjoyable clicks. Overall, side buttons show significant improvements over previous models, particularly the EC series.

Scroll Wheel Performance

Unfortunately, the S2 continues the trend of previous Zowie mice with their less-than-ideal scroll wheels. The 16-step scroll wheel, while favored by some, is stiff, loud, and not pleasant to use. This design choice remains because many users, including pro players, appreciate it for gaming purposes. Therefore, it seems this scroll wheel style is here to stay. As a result, users may need to adapt or consider using a different mouse for tasks like browsing and office work.

Coating Variations

The coating on the S2, while offering a matte finish that enhances grip for sweaty hands, does tend to gather dirt and fingerprints quite easily. In contrast, the EC-B series (initial batch) features a coating that is so shiny it almost resembles a glossy surface. Throughout Zowie's history with mice, most series have been designed with a matte black coating. However, examining these matte coatings reveals noticeable differences among them. Lastly, the coating.

Packaging and Accessories

Packaging Contents

Inside a plastic mold, the mouse is securely placed. A small booklet, warranty information, a sticker, and a set of replacement mouse feet are included in the package. The S2 is presented in the standard Zowie packaging.

Weight Comparison

The top shell weighs 41 g, contributing to the overall heft of the S2. When held, it feels noticeably heavier than the 90 g G403, likely due to its thick shell walls. In comparison to other mice of similar size, like the Endgame Gear XM1 or Razer Viper, which are around 70 g and avoid using holes in their design, the S2's weight is on the heavier side. My scale reads approximately 85 g (+/- 1 g) with a little cable, which is quite reasonable considering the S2's size.

Cable Flexibility

The cable features a gold-plated USB connector and includes a ferrite bead to minimize noise. It measures 2.1 m in length. When comparing flexibility, the S2's cable is similar to the EC2-B, making it more flexible than the Endgame Gear XM1's cable but not as flexible as the paracord-like cables found in the Glorious Model O or Dream Machines DM1 FPS. The S2 utilizes a standard black rubber cable.

In practice, while using a mouse bungee, the effect of the cable's upward angle is minimal. Notably, the cable extends at a slight upward angle, designed to lessen cable drag on the mouse pad.

Foot Design

The existing aftermarket feet, like Hyperglides, are compatible without any problems because the shape of the S2's feet matches those on the ZA11, ZA12, FK1+, FK1, FK2, FK, and AM. Although I personally favored the EC-B feet for their quicker glide, the S2's feet perform adequately. This model, the S2, features traditional PTFE feet that are dyed black and offer a smooth glide. Zowie reverted to their classic design of two larger feet—one at the top and one at the bottom—after receiving feedback about the smaller, non-dyed PTFE feet on the EC-B series.

Shape Design

The S2 is definitely its own unique design, even with its inspirations. The palm support comes solely from the hump at the back, similar to the ZA series. However, unlike the ZA series, the S2 features a flatter hump that stretches almost completely across its width and isn’t as tapered. This low-profile mouse shares a resemblance with the FK series, and it combines aspects from various Zowie shapes. You can spot the length of the EC2-A/B, the overall curvature of the FK2, and the hump placement from the ZA12 in the S2. Also, the main buttons have subtle comfort grooves, which are a nice touch for those who grip with their palms.

The S2 mouse is designed to fit a variety of hand sizes; for context, my hands measure 19x10 cm (thumb included), and I wouldn't want it larger or smaller. It offers enough support for a palm grip while not hindering fingertip and claw grips due to its non-intrusive hump. Overall, I'd say it accommodates the three main grip styles: palm, claw, and fingertip.

Disassembly Process

The design of the S2 makes it somewhat elegant, yet it doesn't excel in weight-saving. The side button PCB is thinner compared to both the main PCB and the main button PCB, which are sturdier, likely for structural reasons. The main buttons, scroll wheel, and side buttons are located on separate PCBs, making assembly a bit more complex. However, taking the S2 apart is quite straightforward. A single screw located beneath the bottom mouse feet holds the bottom and main shell together, allowing easy access to the internal components. The main PCB contains the sensor and the MCU.

For the datasheet, please check this. The part number is CY7C64356-48LTXC, which belongs to the MCU.

It can be assumed that some iterations were necessary, given that the main PCB is labeled "Rev:B" while the main button PCB is marked "Rev:C". One can only wonder why there was a six-month delay in finalizing the rest of the design. Interestingly, parts of the design seem to have been completed as early as 2018. This leads us to two important conclusions. First, no changes have been made to the internals since the initial production of the Divina S1/S2 series. They are completely the same and come from the same production run. Second, looking at the dates on the PCBs, we find that the main PCB is dated 2018-09-17, the main button PCB is dated 2018-09-13, and the side button PCB is dated 2018-01-28.

I'm unable to find any noteworthy flaws in the soldering and overall quality of the PCB.

Sensor Performance Limitations

Starting with the sensor limitations, Zowie has set the PMW3360 to four specific CPI levels: 400, 800, 1600, and 3200. This means you won't be able to access its full potential of up to 12,000 CPI. The maximum tracking speed of the sensor reaches an impressive 250 IPS, translating to 6.35 m/s. As of now, the Zowie S2 features the PMW3360, which is recognized as one of PixArt's top optical sensors.

CPI Discrepancy Factors

In this test, I'm evaluating whether nominal CPI matches actual CPI. Ideally, the goal is to minimize the difference between these two values, even though a perfect match is unattainable. Several elements can affect this comparison, including the mounting height of the sensor not meeting specifications, the thickness of the mouse feet, the mousing surface, and firmware. These factors can lead to discrepancies where nominal CPI does not align with actual CPI when the mouse is moved one inch, which is what "CPI" (counts per inch) measures. However, it's important to remember that individual units may have differing results, so your experience could vary.

Here, we see that older Zowie mice often fell short of expectations, but that's not true in this instance. This is a notable finding because the deviation is impressively low. As you can see, this outcome is a fantastic achievement.

Motion Delay Evaluation

The control subject for this test is the G403, featuring a 3366 sensor that exhibits no noticeable smoothing throughout its entire CPI range. Since there's no precise method to measure motion delay directly, the assessment must rely on comparison with this control. The primary focus of this test is to identify sensor smoothing, which involves averaging motion data over multiple capture frames to minimize jitter at elevated CPI values, ultimately leading to increased motion delay. The aim is to achieve minimal smoothing. It's important to note that "motion delay" refers to all types of sensor lag, and any extra input delay sources will not be factored into this test.

The 3200 CPI plot shows visible "kinks," indicating the presence of smoothing. In contrast, the 1600 CPI plot appears smooth without any noticeable kinks. This difference is anticipated because the 3360 features 32 frames of smoothing at and above 2100 CPI, resulting in an additional motion delay of about 4 ms at the slowest speed. First, I’m examining an xCounts plot to quickly determine any smoothing effects.

The findings confirm the results noted earlier, particularly at 3200 CPI, where the delay difference is about 4 ms. Motion delay remains consistent across all CPI settings except for 3200 CPI. The xSum plots are being analyzed for the four available CPI steps: 400, 800, 1600, and 3200 CPI. Lastly, the line positioned further to the left indicates the sensor that experiences less motion delay.

Speed Variance Management

When discussing "acceleration," what people generally refer to is speed-related accuracy variance (or SRAV for short). The main idea is that the cursor's movement doesn't cover the same distance if the mouse is moved the same physical distance at various speeds. This concept is crucial for understanding how different mice perform. To illustrate this, one can compare it to a control mouse known for having extremely low SRAV, which is the G403. As shown in the plot, there's no noticeable displacement between the two cursor paths, confirming that SRAV is indeed very low. It's not about the mouse having a fixed amount of positive or negative acceleration; rather, it's about this variation in cursor travel.

Perfect Control Speed Management

At a speed of 4 m/s, I've only achieved a minimal performance, but it still falls within the claimed PCS range, showing no signs of sensor issues. The mouse and its sensor can be moved at Perfect Control Speed (or PCS for short), which is the highest speed before any sensor malfunctions occur.

Polling Rate Management

The three available settings (125 Hz, 500Hz, and 1000Hz) are all visually appealing and maintain a stable performance.

Sensor Performance Evaluation

As you can see, there are no issues with sensor lens rattle. Furthermore, no such problems can be observed, including jitter and angle snapping (non-native straightening of linear motion). This test is used to identify any potential issues related to these aspects.

Lift-off Distance Settings

Keep in mind that LOD might change a bit based on the mousing surface (pad). The only available (default) setting is very low, as it doesn't track at a height of 1 DVD. As far as I can tell, the S series does not support adjusting LOD.

Conclusion

In terms of usability, the ability to adjust the polling rate directly on the mouse is a great addition. Overall, the build quality and components are impressive, with no complaints about the clicks and buttons – five in total. A cool feature is the angled cable exit, which reduces surface friction. The Zowie S2 Black is designed for smooth handling, thanks to its decent weight of about 85 g, great gliding feet, a grippy coating, and a flexible cable. The sensor, PixArt's PMW3360, performed flawlessly in my testing, making it a well-equipped option. Its ambidextrous shape and medium size make it ideal for palm, claw, and fingertip grip styles. During testing, the Zowie S2 Black excelled, proving to be a strong contender in the gaming mouse market.

The Zowie S2 is an excellent option for those who can overlook its lack of software or RGB features and are okay with Zowie's high price tag. However, for those who aren't bothered by these minor issues, the S series has significantly improved upon the flaws seen in earlier Zowie mouse models, particularly regarding the side buttons. It's unfortunate that the scroll wheel still doesn't meet expectations, and while Zowie's absence of software customization fits their "competitive" branding, I would still prefer having at least some customization options available.