^waaaay too much koolaid over there.
to the OP, it makes little difference. In large to xl sized frames, you feel like you are sitting more in the bike than on top of it. the wheels are a bit heavier, and bikes keeps its mo' a bit longer. it feels more stable at high speeds, and I think this has to do with a lower center of gravity relative to the axle .
Not that big a deal though. I feel I just fit better on a 29er mtb. I am a lanky 6'2''
If you plan on doing tricks, urban, etc.. you might opt for the 26'' mtb. shorter wheelbase and the ability to run stronger wheels.