First proper mountain bike

[dienamic]

I've been riding my old halfords saracen full sus for a few weeks now, and think I'll probably carry on with the amount of cycling I've been doing for the forseeable future. I have, of course, started looking at shinier and newer bikes! I've read good things about Cubes at the sort of price point I'm looking at, and have been looking at the Acid 29er http://www.hargrovescycles.co.uk/products.asp?cate...
Is there any decent reason not to go for one of these at about a fiver a week (If I describe the cost like that i'm more likely to get it past the wife!)?
It looks to my untrained eye to have fairly decent spec gears and brakes, and a rockshox air fork. Can't find many reviews of the 2013 model, just the 2012 that had a different fork.
Thanks
D.