Did a 70km pootle just this past weekend on my Brommie. Regularly go to work or home via the local 500m mountain on the Brommie.
As for wheels size, I am more than ever convinced that the other frame parts, ie suspension in the Brommie, and long seatpost and stempost, contribute lots to softening road bumps so the wheel size to me is pretty irrelevant. I expect the Tern to be stiffer overall and therefore bumpier despite having bigger wheels.