Being 6'4", I find that the extra substantial feel the tires give the bike basically make it feel larger, and help to absorb the slings and arrows of hard core urban commuting better, especially on a folding bike's frame. I put it through a lot, and the 2.1's are more about keeping the bike together than cushioning my derierre.

The larger feel to the bike makes it feel more surefooted to me. I bought it with the original kenda 1.5s and I'd never take this bike back down to that size tire.

Maybe I should call it the silver ghost. Classier, but less alliterative...