Cosmetically and the way the keyboards feel, the two machines are night and day.
Couldn't comment on the benefits of functionality between 'em (even though I've
owned both), just prefer the original C=64 for nostalgic reasons.
The keyboard mechanisms in the 64 and 64C are actually exactly the same (believe me, I've had them all in pieces) but the newer C64C (short board) actually does have some differences, for one, they're more reliable, but the different chips they used caused a couple of minor incompatibilties, raster dots at certain times and lower volume digitized samples. For the most part, though, they'll do.
