I know a couple of you guys from lan were looking at getting one of
these badboys; I'd advise you to wait and see as I did some reading on it last night and apparently the "incredible high definition dual-eye laser" can't track on black surfaces which for a £50/£90 mouse is a fucking joke! Partly why I got a Kone rather then waiting for one of thses (the other part being dropping £90 on a mouse just isn't possible for me atm). Maybe give it a month after launch (Wenesday I think) and see what the general public have to say about it.
Aside from that though, most of the reviews were really positive, obviously focusing more on the customization then the actual functionality, but still most/all rated it really highly. Good tracking, easy to use software, good build quality etc. I think Ima going to wait until the second generation on this one; its a nice idea and a sexy bit of kit, but I see lots of teething problems with it and for that ammount I'd want something that just straight up works perfectly out of the box really.