Corsair Vengeance M90 and K90 Review @ OCC
 

In conclusion the M90 is a pretty nice mouse; however, it didn't win me over the M60 Corsair released just before it. To be honest I will probably pass this off to one of my MMO-playing friends who might be able to get some better use out of it. Unfortunately, it wasn't just the extra buttons that made me not want to keep it around it was the slightly awkward placement of the programmable buttons as well as the default forward and back buttons that made it just a bit awkward for me to use. The mouse itself worked well, and trust me, it was nice being able to set extra mouse functions here and there – it just wasn't comfortable for my "little" hand. I'd still recommend the mouse, but I still prefer the M60 over the M90 hands down.

http://www.overclockersclub.com/revi...r_vengeance90/