i have the pro-x too! it's very nice. the brush head is very soft and it's 2 speed adjustable. i didn't know how to pop out the battery slot when i first got it though haha.
I love my Pro-X too. It helps with all the little flakies that Retin-A causes around my nose and chin, but is still very gentle. Also it is identical to the DDF Revolve 400x that retails for $95, with the exception that the Revolve includes a dermabrasion attachment.