So I bought a corsair M60. It seemed really large - longer, higher and wider than my Razer Krait. Kinzu seemed too small, others had potential - thanks for the info.
That said, the M60 fits my actually exactly medium hands well. I get what others have said about the sniper button being 1/2" or so too far forward. The width is actually a bonus. It has an etched left side which is nice too - and not slippery.
Initial impressions are very good. The feel of the buttons is good.
Instructions, etc, however, are terrible. I got the manual and software online after looking at a silly "start here" handout that basically says plug it into a USB slot in 4 frames. No mention of software at all in the package.
Now to play with weights and software.
Very much worth a look.