I use a G600 - all the G-keys are assigned to the skill bar. To get to the 2nd row of skills assigned to the F-keys I just need to hit the left ctrl with my pinky and click away on the mouse. Its a pretty sweet setup since I'm playing bard and move around a bit while DPSing to avoid aoes and the like. I think clicking the row of buttons closest to you the G18-G20 keys can feel a little awkward at first, but with more use you get used to it. I also like the fact that it has 3 clicks on the top. So I have Left click - Teamspeak button - right click. I've had a pretty good experience with the mouse so far. The option between mouse profiles is great too. So I can switch between games and already have all the G-keys macro'd to the buttons I want. I'd say give it a try.