AMN had one attached to the one piece shower/bath in her hotel room at the MWGTG and I actually hung on it, and it didn't come off. I was impressed! At 6'2 and 230 lbs, I ain't no leetle chicken like that ol' DM and it held when I hauled on it!
I was actually afraid I would tear the tub/shower away from the wall. They must attach them units just so people like me don't damage them!
Too bad we couldn't say the same for the screens!