3.0 if you're right handed. And have man hands. WMO if you're left handed. Or have child hands. ;)

gtfo

Imo the problem is more simple.

* People who like using palm grip : Microsoft IntelliMouse Explorer 3.0 or razer deathadder (1800 dpi) are the best mouse.

I tried the mx518 during 2 days, conclusion : too heavy

* Microsoft IntelliMouse Optical 1.1A nobody use that, you mean wheel mouse optical 1.1a (WMO 1.1a) probably.

Very good mouse, but just 3 buttons. Razer mouse like razer abyssus, salmosa, and stealserie kinzu are now used too.

Mx518 too heavy? There is a solution.

http://www.youtube.com/watch?v=31g0YE61PLQ