Essentially, the Hati-S Plus ACE and Hati-S Plus 4K are the same mouse, aside from the addition of 4000 Hz wireless polling on the latter. This addition, however, is enough to elevate the 4K above its 1000 Hz sibling by several notches.

Mice limited to 1000 Hz polling are typically USB full-speed devices. When such mice are claimed to be capable of polling rates above 1000 Hz, tricks such as packet duplication to fake readings are used, as USB full-speed is restricted to a frame size of 1 ms and therefore incapable of native polling rates above 1000 Hz. The Hati-S Plus 4K, on the other hand, is a USB high-speed device in wireless operation, and thus natively capable of polling rates above 1000 Hz. By virtue of being a high-speed device, the 4K manages to outperform the ACE even at 1000 Hz. In my testing, wireless motion delay at 1000 Hz sits around 1 ms, which is plain excellent and on par with the likes of Razer or Logitech. Unlike the ACE, the 4K also allows disabling MotionSync, which synchronizes SPI reads with USB polls at a minor latency penalty. At 1000 Hz, this penalty is 0.5 ms at most, but disabling it suffices to bring wireless motion delay down to a stunning 0.5 ms. With 2000 and 4000 Hz entering the equation, the numbers get even better. While 4000 Hz works virtually flawlessly on the Hati-S Plus 4K, I've found 2000 Hz to potentially be bugged, as tracking doesn't behave normally, even though polling itself is stable. I've notified G-Wolves of my findings, and have been informed that a firmware update is being worked on. In any case, at 4000 Hz, the Hati-S Plus 4K is ahead of the Logitech G403 (control subject) by roughly 0.5 ms, which is a feat only Razer has been able to achieve with the HyperPolling Wireless Dongle on a wireless mouse before.

The highly impressive showing in terms of motion delay is complemented by an equally strong showing when it comes to click latency. The Hati-S Plus 4K allows adjusting the debouncing method for the main buttons in the software. When using the lowest setting, eager-type debouncing is used, which nets the lowest possible latency but may result in slam-clicking, which describes inadvertent button actuation upon resetting the mouse. The main benefit of eager-type debouncing is that no additional latency is introduced compared to defer-type. Higher debounce settings add higher levels of defer-type debouncing, which increase click latency. At 1000 Hz in wireless operation and when using the lowest debounce setting, click latency is just 0.8 ms, which is 1.5 ms lower than what the full-speed ACE has been able to do, and easily bests the Logitech G Pro X Superlight or recent Razer releases such as the Viper V2 Pro without the HyperPolling Wireless Dongle. When set to 2000 or 4000 Hz, click latency is even lower at just 0.6 ms, accompanied by lower standard deviation.

In short, latency is simply stellar on the Hati-S Plus 4K, and this applies to other areas of sensor performance, too. CPI deviation is appreciably low, general tracking excellent when using MotionSync, and all polling rates are perfectly stable both in wired and wireless operation. Unlike the ACE, the Hati-S Plus 4K also has no smoothing across the entire CPI range, which is beneficial when wanting to saturate 4000 Hz, as one can use a higher CPI step without any latency penalty. While the ACE exclusively comes with PixArt's PAW3395 sensor, my sample of the Hati-S Plus 4K is equipped with the PAW3399, whereas later batches are said to feature a PAW3395 as well. Being a variant of 3399, the 3395 is equally suited as the 3399 for 4000 Hz polling, as both sensors are able to achieve a sufficiently high framerate. Hence, the 3399 and 3395 version of the Hati-S Plus 4K should perform identically.

Of course, 4000 Hz polling isn't without downsides, the main one being increased power draw. Whereas the Hati-S Plus ACE could do with a meager 75 mAh battery and still achieve battery life upwards of 25 hours, the Hati-S Plus 4K requires four times the battery capacity to do the same. As a result, the Hati-S Plus 4K weighs 5 g more, at a still highly competitive 51 g. Much like the ACE, the Hati-S Plus 4K only has holes on the bottom, and utilizes the PCB to reinforce the shell. The result is a mouse that is exceptionally light yet does not creak or flex at all. That said, I do get a rattle when shaking my unit, though I don't know what may be causing it. All I can say is that it comes from something on the PCB, but it's not the sensor lens or scroll wheel, which doesn't leave many possibilities. The design does come with a limitation, however, which is the on/off-switch. Since the slider does not sit flush with the bottom shell, a tool has to be used to access it. G-Wolves includes two sticks in the box, but I've found cylindrical bodies such as a ball pen to be more convenient. According to G-Wolves, the idea is that the mouse only needs to be turned off rarely anyway, as when not in use, the mouse enters a sleep mode whose power draw is minimal to where turning it off barely makes a difference. I've found this to indeed be the case, which is why I don't take issue with this solution.

As mentioned, the Hati-S Plus 4K comes with a 300 mAh battery, and G-Wolves cite a battery life of 22 hours at 4000 Hz and 80 hours at 1000 Hz. The software includes a basic battery level indicator, which is reliable enough to allow me to gauge expected battery life. After 10 hours of continuous use at 4000 Hz, the indicator showed roughly 50%, so the numbers given by G-Wolves appear to be accurate. Charging is exceptionally fast on the Hati-S Plus 4K, topping out just short of the USB current limit. Hence, the charging cable not being the most flexible isn't much of an issue. In addition to the charging cable, G-Wolves also includes an extension cable for the wireless dongle, which may as well be used for charging. Since the extension cable is quite short at 0.90 m, the charging cable may be used instead, as I didn't find any differences in polling stability and general performance between these two cables on my setup. That said, being shorter and having better shielding, the extension cable should be used preferentially for the dongle if possible, as signal integrity will be significantly better compared to the charging cable.

When it comes to the buttons, the Hati-S Plus 4K is no different from the ACE. Zippy DF3-P1L1 (60 M) switches are used for the main buttons, which provide a firm and snappy button response without being overly stiff, some pre-travel notwithstanding. On my sample, the left main button occasionally emitted a "thock" sound upon release depending on the angle the button is actuated from, but this disappeared after disassembly. Since the ACE didn't have anything like this in the first place, I'm inclined to file this under one-off. The side buttons too are very nice, with low pre and post-travel, and the back button cannot be pushed in as far as it was possible to do on the ACE. The scroll wheel too is the same, utilizing an encoder from TTC which provides very tactile scrolling at elevated noise levels. As for the feet, the default ones already glide well, and G-Wolves includes several sets of replacement feet. Since the bottom of the Hati-S Plus 4K is level, feet of virtually any size or shape could be installed instead, which is smart design.

Much like on the ACE, the software for the Hati-S Plus 4K is a simple executable that can be run without requiring installation. When using the latest firmware, the latest software should be used in conjunction with it, but unlike on the ACE, using the older software does not affect click latency negatively. Not having to install anything is highly convenient, all setting changes are saved to the on-board memory, and I didn't find any bugs per se, only the occasional error when the mouse had already entered sleep mode. Unfortunately, the latest version has a substantially higher RAM footprint compared to earlier ones, though still low enough to not be much of an issue.

Overall, the Hati-S Plus 4K is plain excellent. Even the pricing is reasonable, given that Razer charges at least $150 for their 4K-capable mice, and the $30 for the HyperPolling Wireless Dongle come on top. Given the meager $30 premium over the ACE, I'd even go as far as saying that the Hati-S Plus 4K renders the ACE obsolete, as the 4K does everything better, regardless of which polling rate is used. As such, the Hati-S Plus 4K earns our Editor's Choice.

The only direct competition the Hati-S Plus 4K gets is from Razer, by virtue of being the only other manufacturer currently offering true 4000 Hz wireless polling. The Razer Viper V2 Pro retails for $149.99, weighs more, has similarly good buttons and optical main button switches, and similarly good performance, which can be improved even further with the $29.99 HyperPolling Wireless Dongle, but suffers from its resource-heavy software. The Xtrfy M8 Wireless too weighs more, has comparable performance, similarly good buttons, and no need for software, for $99.00. Likewise, the Pulsar X2 Mini and LAMZU Atlantis too weigh more, have comparable performance, similarly good buttons, and the software is lightweight, for $94.95 and $89.99, respectively.