I have the Steelseries Xai which this mouse is largely based off of.
I spent hours toiling to find a suitable mouse - Razors drive me nuts (they suck so much its not even funny), other mice are too plain or are one handed which I find annoying. I finally ended up on the Xai because it was literally the only mouse I could find that met my qualifications.
The shape of this mouse is fantastic, and combined with their $20 mouse pad, it makes all the world of difference in games.
The only issues I have with Steelseries is the quality of the materials they use, the springs in my first Xai died and I had to RMA it. Steelseries initially balked at my RMA request which is my second gripe with them. They give 2 year warranty in all countries except the USA which is only 1 year (my mouse was a month or two over a year old). I advised this is a poor way to treat a large portion of their customer base and they relented and shipped me a new mouse.
The price is also a tad high but hey until they get competition, they can charge it.
I would recommend this mouse to anyone.
Edit: I did have problems with the xai in an older amd rig during boot it would lock up until I unplugged the mouse
![Er... what? o_O o_O](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
, replace with POS old Razor and problem solved. I suspect the Sensai might have the same issue.