The Sherpa is a great XC bike,but I would be more tempted to go for the Switchback.
Slacker Geo means more scope for a longer travel fork,thus if you want to hit some off piste for a bit more aggressive XC rides and hitting downhills a lot more confidently
Good choice on the brand incidentally.
That all being said,the Sherpa is a very capable Trail bike.
Are you going for speed rather than jumps,tight technical stuff and twisty DH ?
If so,the 29er Sherpa is the obvious choice
I went for a test ride around Swinley and absolutely loved the bike - it was a no brainer. Spoke at length to the owners too (great blokes and proper bikers). For the money you pay you get a fantastic deal and a very capable bike. I love the Stantons but I wasn't prepared to pay the money they wanted for a bike that's no better than the Bird, IMO.