I will say this about that.
if you ahte the 510...you will hate the G5.
The scroll wheel is harder to middle click on the G5 becuase it wants to "slip" to the side thanks to the side scroll. It takes a few days to get used to it unfortunately.
So beings that the middle mouse/scroll click was your biggest pet peve, stay away from teh G5.
Unfortuantely, the mouse you describe, i think its made of unobtanium.
And, off the top of my head, i cant think of any gaming mice that are worth beans that come close to teh features you want/need as a gamer. But ill be thinking.