I have the previous version G502, it appears the only appreciable difference in the new one is the ability to control the LED colors. I have to say it handles sweat well, I can't notice much difference holding it with a sweatier palm. Most of the buttons aren't really sharp in my experienced, they may look that way in pictures at first glance but they're actually pretty well rounded or contoured, it probably wouldn't bother you.
The only complaint I have with the mouse is that the scroll wheel feels kinda clunky, I did prefer the smoother scrolling on my old Razer Taipan, but it is a trade off because you can switch to a free-rolling mode, and the side buttons, both of which Razer doesn't have.
Unless desktop fashion is really important to you and you really want to be able to change the LED color, I would probably just snatch up some of last year's models for a lot cheaper.