at low speeds it may seem less manueverable, but at high speeds this translates into more controllable. take one out for a nice LONNGG ride, and by the end you will get it.
i was a 26" hold out claiming there was not a big difference, 29ers must handle like a truck blah blah blah, but now that i have one MY GOD they are so much faster downhill. the better angle of approach of the larger wheel keeps you speed up given the same bumps, and the additional momentum i feel helps on the climbs. traditionally people say smaller wheels climb better, for the road maybe, but in the dirt where there are large bumps (26" bikes) the bigger wheel is king.
just hope you're tall enough!