I like slack bikes and bought a whyte on the bases of a test ride, that felt 'just right' to me. That said, my 26er FS bike has the same head angle, the 29er does not feel the same (as slack).
I'm left wondering how how Whyte have managed to get it so right, when supposedly the industry says 70° are as slack as you'd ever want...
Anyways, dependant on the size of your pocket, I'd add last years Whyte 829 (sold with 100mm & a 69°) which should come very close to the 2013 929 with 120mm & 67-68° headangle. So would probably handle the upgrade to 120mm well. The 829 seems to be a bit of a dark horse that many ppl have over looked (& the ones I've seen for sale 2nd hand had little interest) and the 929 sold out so quick, they seemingly never hit the showroom floor.
The 5/6/729 range are great bikes too, but the 8/929 ability to shorten the chainstay makes them that bit 'better', there well worth chasing down IMHO
The 929 IMO is a Yelli for more jey-core or XXXXC rider
oh and everyone seem to have forgotten the 2Soul's Quarter Horse