I'm in a similar situation with more body than legs. (6'3", 33" inseam) I'm kinda thinking that the 29er will have a longer top tube to accommodate the slightly larger wheels, that might help.
What Crypt says is hard to top and fits my thinking. Lighter means less work, smaller means nimble. Comfort means you will want to ride more. Stems and seat adjustment can make up for the tops tube length and get your body in good position.
What is your primary riding interest? XC, downhill, racing, camping, recreational sightseeing?
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I think its disgusting and terrible how people treat Lance Armstrong, especially after winning 7 Tour de France Titles while on drugs!
I can't even find my bike when I'm on drugs. -Willie N.