If you set the S command and the P command to do similar pitch bends, you'll notice that the S command has a choppiness to it, and the P command is a nice SMOOTH pitch bend.
Very much so, and since S command only works in Pu1 and not in Pu2 and it's choppier I think I've only ever used it for the noise channel, it's good for glitchiness, but not much else as far as I can tell.