I picked up a couple of PW motors from the Fiero Store during one of their sales. My windows are slow, but looking at the repair to replace them looks like a PITA. I don't like taking panels off (I always seem to break something along the way). One of these days, I'll try the slow window fix.
I replaced my switches and still had slow windows. The driver's side more than the passenger. It got to the point that I'd have to help the window go up by pulling the glass as the switch was pushed. I lubed the tracks, still no good. I dreaded replacing the window, but forged on and picked up a motor at my local discount parts store.
I was really surprised that it was not all that difficult to replace. I drilled the factory rivets out, and replaced the with 1/4 bolts and nuts. There is a tutorial on the forum that made the job pretty simple.