[Closed] Scott Genius 930, 2013, any good?

I've found a 2013 Scott genius 930 for £1599 at my lbs reduced from £2799, it represents a good deal spec wise but I've never ridden a 29er,
I'm currently riding a 26 inch hardtail. I want a full suss bike but am I better going for a 27.5? What's the difference between the 3 wheel sizes apart from the obvious size, do 29 ers roll better?
Also there's a scottsoark reduced to £1400 that to is a 29 er but only 100mm travel, is that enough travel on a 29er for trail centres/moors trails etc?, not a downhiller just the red/black routes