Yeah, right, since the 27" rim has a larger diameter than the 700c rim it will, in theory, roll over objects more smoothly. Putting a fatter tire on the 27" rim and a thinner tire on the 700c rim will increase this effect, while putting a thinner tire on 27" and the fatter tire on the 700c will decrease it. In theory.

But let's not confuse the theoretical issue with reality. In reality, if we are talking about different bikes with different geometries and different tires, it is just silliness to pick one of many minor differences --in this case a difference of under 1.5%-- and say "I can feel the difference!" I'm sure you can feel a difference, but the diameter of the rim has nothing to do with it. The frame geometry and the specifics of the tires (dimensions, thread count, pressure, &c) have a much greater effect.

I usually ride a bike with 20" wheels, and it has a much smoother ride than my bikes with larger wheels.