Try autodesk sketchbook. free trial, and cheap for purchase if you like it. WAY faster than painter. no fancy faux-media brushes, but I don't care for those anyways. Give it a shot.
ended up going with ArtRange for now, playing with this today. downloaded the demo of painter 12 - and really like that, but would rather see if this (digital painting) is something i'd like to get into or just a phase before i spend real money.