The reason I am removing one star is because after 13 months of use, the scroll wheel started to "jump" and randomly reverse its direction, and generally became unusable. Looking online, I saw that this is a common problem, and for some people it doesn't get resolved...

FORTUNATELY, in this case the problem was solved after carefully cleaning the side surfaces of the wheel, pressing the buttons to better expose the wheel.

The sensor "reads" the movement of the wheel optically, so dirt creates the problem. Thank goodness for my wife who thought of it... but for a mouse of this category, it's a bit disappointing to need something like this.

Other than that...

The mouse is exactly what I was looking for in terms of size. It's about 13 centimeters long, and by today's standards it's considered HUGE. I have no experience with any MX model from Logitech but for example the M650 L (L = large) is 12 centimeters...

The battery, with heavy (12+ hours) daily use, easily lasts over a month with bluetooth. With the wireless USB dongle, cut the duration in half. Either way, if you "run out", you connect the mouse to the cable and continue to use it normally while it charges.

I use the Razer app because I have other products from the company... but if you don't want to, the app is not necessary. However, through it you can see the battery status. Otherwise, a light on the mouse notifies you when it needs charging.

The charging cable, in the version I have, is microUSB which for me is not an issue. The newer Pro Click V2 has a USB-C connection.

Probably the best mouse I have ever tried (I haven't tried vertical mice). Lightweight, accurate, high-quality, ergonomic. I use it for work and I didn't bother trying the Razer application, nor do I intend to. The only button I tried is the small one on the top that seems to change the dpi or the speed/sensitivity of the mouse. Recently, I have used a Microsoft Sculpt Ergonomic and a Logitech M720. It is clearly better than the Microsoft, which is not worth even 1 euro. Compared to the Logitech, it is bigger, lighter, and seems to not have the same plastic coating that Logitech has, which deteriorates over time.

So, it has three disadvantages and loses one star:
- It doesn't have a switch between two scroll modes like the M720, meaning the wheel doesn't spin freely. If you get used to it on the Logitech, you will miss it.
- The port is not USB-C but USB mini, and a common cable may not fit - it comes with one in the package that fits.
- It is expensive for 85 euros. Not that it is not high-quality and good, but I think 40-50 euros would be a better price. Here, we probably have the phenomenon of "a good mouse costs 70 euros and above"...

I am not a gamer and I have never had the experience of a Razer. Finally, I bought it on 15/7/2022 for regular use and I am - so far - completely satisfied. Its size is for desktop computer. The fit in the hand is ideal. It is slightly lighter than I would like and its keys are not silent, but still less noisy than other mice (I mention this as information because I am not interested in this issue at all). The scroll wheel is precise, it protrudes a bit more but it facilitates the use of the right & left tilt switch. The two side buttons are in a very good position suitable for comfortable access by the thumb. The dpi is excessive for non-gamers, it goes up to 16,000! I have left it at the minimum, 800 dpi. Very good and seamless connection both with USB and Bluetooth. Great accuracy in targeting and confidence in pressing the buttons. The related software (Synapse) is excellent, you download and install it in a minute and it has a large number of settings as well as visual representation of changes in operation. If you look for the battery, you won't find it: it is internal, rechargeable and not accessible. It charges from a micro USB located on the front of the mouse, which turns it into a wired one during charging (the relevant cable is included in the package). Of course, you can use any charger you want with the available cable (only the one it comes with and its drivers). However, if the battery runs out, the mouse can still be used but as a wired one and I don't see a way to change it except through a service center (?). Its battery life is relatively long compared to the increased capabilities of the mouse. It lasted for about 20 days with intensive use until it needed to be charged, so everything is good - not as good as some Logitech mice, of course. I should not forget to mention that the device is very beautiful, it looks sturdy and well-made, and the assembly of the plastic is flawless. Conclusion: the mouse is excellent and high-quality in every aspect without any noticeable drawbacks. However, because "experience is the best teacher," I rate it with 4 stars (not 10 as it deserves) while waiting for its reliability to be tested, so I will come back with further updates.
Update 1: Unfortunately, it seems that the white coating of the mouse is peeling off and exposing the underlying material. The underlying material is still white (fortunately), but I am afraid that the "Razer" logo is about to disappear. These are construction-related issues and are not flattering for a device that costs €100 and is used for many hours daily. However, its functionality remains excellent as I have described in my initial review.
Update 2: Important observation - Be careful not to lose the charging cable. The USB plug has special guides on the side to fit into the mouse's port. Standard USB plugs do not fit and you have to "wiggle" their side plastic to narrow them down and fit.
Update 3: After extensive use, the side button x1 (back) has a slight sticking issue. When you press it once, it feels like it is pressed for a second time (milliseconds later), causing the programmed action to repeat. Additionally, the mouse goes into sleep mode after a maximum of 15 minutes. This cannot be canceled by Razer software (synapse), it can only be delayed for up to 15 minutes and then you have to reconnect it to the computer.

If I were to change 2 things about this Mouse, it would be:
1. Its weight, I would really like to see it at 80 grams. It is a large ergo palm grip Mouse and it is logical for it to be heavy due to its size (the equivalent Logitech Mouse weighs 141 grams, which I consider to be a brick) but if the weight was lower, it would further reduce the chances of developing tendonitis, as most people who work on their PCs have high sensitivity and make wrist movements. The 100 grams that the Mouse weighs is LOW for its size, I just would like it to be "ideal".

2. I would lower the Mouse's Specs. There is no reason to have such high precision in the mouse sensor. Even if someone is drawing with the Mouse, they don't need to have the "ultimate sensor" in the mouse. This way, you increase the battery life and significantly reduce the price of the mouse. It is worth the euros that the Mouse costs, but not everyone is willing to spend that much money, especially when they are not used to such prices in office products and cannot easily appreciate its value.

Apart from that, the mouse is incredibly convenient and is my companion mainly for Video Editing and for use in my work. Its design is incredibly convenient and relaxes my hand, unfortunately it doesn't suit me as much in Games (especially in FPS Games) so I can't have it as my Main Mouse in general, but for use in anything else, I prefer it over all the mice I currently have.

I haven't encountered any problems yet, such as Wireless or Mouse Switches. But from what I have seen, people also don't mention having problems, so that's a positive.

I highly recommend it to anyone who wants an ergonomic Mouse.