Edit:2 Year Update:As of currently, July 2023, I have been daily driving this mouse for over 2 years. It is still going strong. The optical switches are still the most reliable and responsive switches I have ever used. Even after millions of clicks and hardcore daily usage, this thing is as reliable as the day I got it. I can count on it to make clicks exactly when I intended to, never double clicking and never false triggering. Gamers know just how important this is.Battery still easily lasts for 2 days with constant usage and RGB brightness at the default 30%. Aside from the textures on the sidegrips having been worn completely smooth where the tip of my thumb rests and some discoloration of the skates, you practically cannot tell that this mouse has ever been used.I did run into a bit of trouble with the middle click requiring harder presses to register at one point. However, all I had to do was bang the mouse a couple times on the side against my mousepad and blow on the scroll wheel with pressurized air, and it has been working normally again ever since. Truly, nothing can faze this mouse.Of course, I should address that during those 2 years, Razer has updated the Viper series. To put it bluntly, the Viper V2 Pro is not worth it at all unless you value a 16g lighter weight over absolutely everything, on a mouse that is already extremely light. The V2 Pro lacks tons of features including side buttons on both sides, docked charging, and RGB. It also has a smaller battery. With this original Razer Viper Ultimate practically being permanently on sale now (being a "previous generation" mouse), it just has too much value over the new Viper V2 Pro, making the decision a no-brainer.In 2023, this is still the greatest mouse I have ever used, hands down. I still find it extremely comfortable in my hands. And there is no greater feeling than to know that I can always rely on this mouse to do exactly what I want it to do, 100% of the time.Razer, you'll have to do WAY better than the Viper V2 Pro to beat this Viper Ultimate.(P.S., Synapse is still terrible. It has no problems switching profiles anymore, but now it will occasionally go crazy with the CPU usage.)_____________________________________________Original Review:To preface - I find it very difficult to find a mouse shape that is comfortable for me. My hands are roughly 19x10 cm and I use a full palm grip. My favorite mouse in terms of comfort is the Corsair Nightsword, followed by the Corsair M65. I also owned the Razer Basilisk, which is comfortable at first, but starts to cramp my hand with extended use.I have long been searching for a proper wireless mouse with a good RELIABLE connection, rechargeability/good battery life, a reasonable price, and of course above all, a good shape. It's no secret that the Viper Ultimate and the G Pro Wireless have been hailed as the best wireless mice around, but the price always kept me away from giving them a shot. Plus, I had heard about double click issues with the G Pro and the shape looked too ambidextrous for me. The more contoured shape of the Viper Ultimate and its optical switches caught my eye more. So when Prime Day came around and I saw the mouse + dock combo at $89.99, I jumped at the opportunity. (I would definitely not recommend paying $150 or even $120 for any mouse, it just isn't worth it.)Shape: 9/10I was scared of this the most since very few mice are comfortable to me. But when I started using the mouse, it felt great, to my surprise. Sure, the hump is a lower than I would have preferred, but my hand can rest very naturally on it with no cramping or fatigue. The low profile and relative lack of contours on the side make it slightly hard to pick up without it feeling like it's slipping out of your hand, but the incredibly light weight certainly makes up for it a bit. I didn't give it a 10/10 because for me, it still isn't as comfortable as the Corsair Nightsword (which feels like it was practically molded for my hand). Overall though, very comfortable and I plan to use it as my main mouse.Buttons: 9/10The main buttons are a 10/10 for me (Left click, Right click, and Scroll Wheel/Middle Click). They feel crisp and snappy with just enough feedback. I can definitely notice the optical switches. Every click feels EXTREMELY fast and responsive, but not in an oversensitive type of way. I use a mechanical keyboard with optical switches, and that has held up very well with 0 misfires or double-presses, so I am hoping for the same from this mouse. Every one of my mice with standard mechanical switches has ended up double clicking after some time and having to get replaced. My only problem with this mouse's buttons are the side buttons. They are way too recessed in the mouse (almost flush with the body) and I would definitely prefer them to stick out a bit more. Aside from that the buttons are very well built, with 0 wobble and a nice click.Software: 3/10Sorry Razer, but synapse just sucks. (Take some notes from Corsair please).The profile switching for recognizing different programs is extremely slow, causes the mouse to freeze up for a few seconds, and can even "crash" the mouse and require it to be turned on and off again. Apparently some other uses said this is because Synapse literally uploads the new profile to the mouse every time you switch programs, which is a terrible design. There IS a workaround, made possible by the fact that this mouse has on-board storage. Store the profiles you are using on the mouse's on-board storage, and you can use it without a hitch. However, this is really no excuse for Synapse to suck as there are plenty of other Razer mice that do not have on-board storage.The other big problem with Synapse is that macros do not immediately stop after you release a button - they will continue playing to completion. This severely limits the number of applications where you would choose to use a macro as this makes it too unsafe to use in many situations.Wireless: 10/10 (With the workaround stated above)Great connectivity - extremely reliable and responsive, as long as you use the workaround for Synapse. Switching profiles without the workaround was the only time the mouse would ever hiccup/disconnect. With the work around, it is just as reliable as a wired connection. And when the mouse goes into "sleep" mode, I hardly notice a delay when I wake it up.Sensor: 10/10Great sensor, combined with the low weight and low-friction gliding feet the tracking is silky smooth. Lift off distance is extremely low as well and can be further adjusted in Synapse.Weight: 10/10Extremely light. Do I sometimes miss having a sniper button to lower my DPI? Sure. But do I need it with such a light mouse? Certainly not. Any small micro-movements are extremely easy to make and it requires little to no-effort to move this mouse.Battery Life: 10/10I've been using this mouse with the default setting of 33% RGB brightness, and when I'm actively using the mouse at the computer for the whole day (12+ hours), it barely goes down to 70%. For less intensive use, you might last a whole 5 days without charging, or even a whole week. If you turn off the RGB, you could go for even longer._____________________________________________Final remarks:While the shape doesn't quite reach the 10/10 comfort that the Corsair Nightsword is for me, it is still extremely comfortable at a 9/10. Had I not experienced the Nightsword, I might have rated this a 10/10. It is comfortable enough that, combined with being wireless and having optical switches, I am completely sold on it. It is now my new primary mouse.The buttons are great, and I have high hopes for the reliability of the optical switches as Razer is the mouse maker currently using them. Wireless connectivity and and battery life are amazing. Synapse is the only thing that sucks. Razer please fix the software - it's borderline a dealbreaker that makes me reluctant to ever consider Razer products. If you ever see this mouse on sale, I highly recommend it. Just don't ever pay more than $100 for a mouse unless it was signed by Bob Ross.