Don't go 29" unless you can try it at a local trail first, they are quite different in the way they ride and will suit certain terrain more than others.
Not a big fan myself. Certainly find that 650b feels the best out of the whole 29er, 96er, 69er and 650 larger wheel stuff.
Would rather stick with 26" for all round riding really but they are pretty good for full on xc.