This is a few days old but I can't let this slide without a single negative review.

I bought a Naga and tried my hardest for 3 days to get used to it. PvE, PVP, Whacking a dummy for hours... I just couldn't do it. I used the trainer pieces (little bits of rubber you can stick to some keys to make finding them easier) but I just couldn't get my thumb to properly contour to the thing. It felt too light and offered little resistance against my thumbs own force, meaning that pressing a side button actually caused me to move my mouse to the right a little bit. Turning, navigating your mouse on your screen, and also thumbing the massive keypad on it proved to be too much for me. I play a feral druid and I easily bound every button on the damn thing (including shift modifiers). Maybe this had something to do with it.. maybe not. I tried hard to love it (and I even convinced myself at first that I did love it as to justify the 100$ i spent on it) but ended up returning it to Best Buy that week and buying a basic mouse with a right and left side button.

The good part - it was incredibly smooth and made me realize the massive difference a good mouse makes in terms of FPS while on the move.