Good but not Perfect.For this review, I'll be comparing this mouse to the Logitech G502. I recently purchased both mice and have had a few weeks to use both. They are two of the most popular gaming mice on the market and direct competitors, so this comparison should prove useful for some.First off, this is the most beautiful mouse I've ever seen. The build quality is incredible and a huge step above any mouse I've used before. The aluminum chassis, rubberized top and sandpaper-like sides make for an incredibly well crafted device. The switches have what I would consider elegant actuation, with good tactile feel that is smooth with a satisfying, muted click noise. The scroll wheel feels elegant as well, with a really nice rubber material and super smooth scrolling action. The LED implementation is also really nice, with a beautifully lit scroll wheel area and brilliant illumination on the back of the mouse. This mouse illuminates the mouse pad and just looks really great, with the option to cycle through the RGB colors or use static colors. In short, its the best built and best looking mouse I've seen, and possibly the best looking peripheral I've ever used- on par with Corsair's gorgeous keyboards. Compared to the G502, this mouse is a step above in build quality and looks.The tracking on this mouse is excellent. It contains a pixart 3360 sensor, regarded as the best optical sensor on the market. The tracking is extremely accurate. The G502 contains a 3366 (Logitech's variant of the same sensor), so they are very similar. Having said that, I do feel that the G502 is slightly more accurate and responsive. Its hard to articulate what the difference is, its more of a feel you get using both mice. The G502 just seems to track basically perfectly, whereas I did have slightly more trouble aiming with pinpoint accuracy with this mouse. In reality though, the difference would probably be imperceptible to most users.The location of the "sniper button" is right where your thumb would normally rest. This would present a problem, but the button does require decent actuation force, so I never found myself accidentally activating it while playing. I was able to lift the mouse just fine as well. I do like the location of the "sniper button" on the G502 a bit more, where its located just at the tip of your thumb. It totally prevents any accidental press of the button, and just felt a little more natural to me.Now we get to the main issue I have with this mouse, and the reason I deducted one star. The shape and weight of this mouse will not be for everyone. Its shorter than most mice, while also being a bit stocky and wide. I use a fingertip type grip where my palm sort of floats above the top surface of the mouse, so I didn't have much of an issue adapting to the shape. However for those with a true palm grip, I doubt they would find this mouse comfortable. I think its probably made mostly for claw grip, and probably most fingertip users will find it comfortable as well (such as myself). However in comparison to the G502, this M65 is decidedly less comfortable. The G502 fits me like a glove. I especially like the extended thumb rest on the G502, and I prefer the grippy textured sides to the sandpaper-like sides of this M65. Aiming and lifting just feels more natural on the G502 for me.The weight of this mouse is probably its major issue. It comes with 3 weights installed in the underside of the mouse, and its just plain heavy. With the weights installed, I found difficult in lifting the mouse without my fingers slipping, and quick wrist actions for aiming are a bit more difficult than on lighter mice. I find it interesting that a mouse marketed as an FPS mouse would be so heavy out of the box. I removed all 3 of the weights, and its definitely much better. The G502 is also considered a heavy mouse, but it comes without the weights installed. I think without weights, the M65 still feels slightly heavier than the G502. Its definitely something to keep in mind for people who prefer lighter mice. The mouse is just heavy, no getting around it.Other than the stock/short size and the weight, this mouse is incredible. It looks so elegant next to my Corsair K70 keyboard, and it just exudes a quality of build that I've never seen in a mouse before. Most mice are full of plastic, as the G502 is. The M65 will instantly impress you with how well its made and how great it looks. However, looks are not enough for me to recommend this mouse over the G502. I think the G502 is probably the best mouse I've ever used, even though it looks overly "gamery" and has a plasticy build quality. It just sports more cool features (free scroll wheel being my favorite) and is supremely comfortable. However for those of you who have owned Corsair mice in the past, or who prioritize looks over slightly better performance, the M65 Pro RGB is a wonderful mouse. I would consider it the second best mouse I've ever used, and this is coming from a loyal MX518 and G400 user.TL;DR:Pros: Great build quality, most beautiful mouse everCons: Odd shape and very heavy.