One thing I can tell you about microdermabrasion is that it doesn't produce dramatic results. It removes the top layer of dead skin cells, and leaves you feeling refreshed. The skin feels very smooth and soft after having the flaky dead skin removed, but doesn't do anything to lessen scarring or smooth out pits (at least it hasn't on me).
That said, the instrument that is used can be adjusted, so maybe using it at a stronger level might to the trick, but that's something that you'd want to talk to a professional about. I would definitely get a few opinions before spending the money, as you may need something stronger for the pits. I use the microdermabrasion more as an anti-aging treatment and general complexion booster (I'm 48 and still suffer from severe acne.) For my acne, only chemical peels seem to do anything. But that's just me. Everyone's skin is different.