I bought this mouse to replace my Razer Naga which eventually died after three years of almost daily use. I do a lot of CAD and spreadsheet work, and having used an MMO mouse for both, it was like working with my hands tied behind my back without having them. I chose the G600 and G13 controllers because both were half the price of the Razer equivalent. Here's what I think: Build quality and functionality: The mouse looks solid so far. The buttons don't feel cheap and their quality seems on par with the Razer Naga despite being cheaper. I have no complaints about the functionality of the mouse, but I'm not an advanced gamer, so DPI, latency, etc. don't matter to me. The buttons on the side are easily accessible and easy to press. The Naga had several buttons on the top center of the pad that I always found difficult to press due to their small size and the curvature of the keyboard. The G600 also has a large mouse click pad that you press with your pinky to get a second set of commands to use on the fly on the keyboard. I did something similar with Naga, mapping the macro to the buttons under the mouse wheel, but it's MUCH more convenient. The G600 is definitely better in this regard. Ergonomics and Aesthetics: The G600 is larger both in terms of size and buttons. As I said above, I like the fact that the buttons are bigger than the Naga as I can now press everything easily. However, I find the G600 a bit clunky. . I can understand why some other reviewers with small hands had issues with the G600. If I just needed a mouse without all the extra buttons, the Naga would be more comfortable to use. To be honest, I don't think it's aesthetically very good. I have no preference. Software: Key mapping software is very important to me because I have so many macros. The G600s software offers many more options as well as simpler viewing and editing commands. The Razer software is easier to learn, but many of its features are hidden and hard to find. Again, I don't use it for gaming, so I can't talk about heatmap features or auto-switching between games. Overall: I like the G600 more than the Razer Naga, but wish it was a little more comfortable in my hand. . I'm a little concerned by the reviews that the buttons stopped working after less than a year. If so, I'll come back and give the mouse a star.