Good to know there's an option for odd size doors. Although, I think it will leave the same marks as the Iron Gym, which are tiny and rub off. They are the contact points of the foam on the moldings.
The UDs are the one that I used to recommend, but $30 vs $60 is a big deal for most people. $30 at Target is an easy decision.
If you compare the Iron Gym and the UD5 or UD6, I think that the UDs are far more solid. The IG needs to be bolted together before you can use it.
If you're planning to do a lot of wide grip work, the handles being away from the wall is a BIG plus. There is no neutral grip positions on the UDs, though.