Seeing as everyone else is chiming in for the Crush, I'll add some balance to the mix…
The Altitude is an awesome bike, buy one with confidence… Geometry is all but identical to a Cotic Soul, and they ride very very similar, which considering the Soul's popularity should tell you something!
Don't get me wrong, I think the Orange Crush is a very good bike for the money, I just think the Genesis is a better long term bet. I've got the 853 version myself and I love it. What would I swap it for? An Altitude Ti possibly if I had the cash, but other than that, nothing… You can't underestimate the ride quality of a good steel frame with spot on geometry, it's so much more involving than an ally hardtail frame IMO.
Either will be a great bike, but I'd definitely get the Altitude out of the two…