Having played with the N7 tablet for a while now, I suspect your impressions are correct. It is not as smooth as my Galaxy Nexus phone, despite the two devices having the same number of display pixels, and running the "same" operating system (well, from the same base source code anyway).

Given the N7 was a "rush job", it appears they haven't had much time to tweak it for "buttery smooth" operation, compared with their flagship device (the GN).