Not for me. I use a Wacom (with Illustrator, not PS, but same diff) and flipping around the the pen to erase is really no different from using a regular pencil. Except way faster.
Since I can use layers and selective editing and save off versions I feel much more relaxed doodling and exploring this way. It's trivial to save the interesting ideas while obliterating the crap.
If I really wanted to start fresh, select all -> delete is quite fast.
The big wins for pencil and paper are: ease of transport and accessibly (much simpler to carry around a sketch pad and some pencils); the tactile feedback; the resolution.
Much as with using a word processor vs. a typewriter and some Wite-Out there are interesting psychological differences at here, too.