I had a prepaid hotel room in Vegas--not Marriott, but they put a hold on my credit card for the full cost of the room that was on the back of the door and nobody pays plus something for incidentals. It stayed there for two weeks. The room was prepaid, so why a hold for anything but incidentals?

I once tried the cash upfront at a Residence Inn, but they insisted on a card also. They took the cash and put a hold for the room cost plus incidentals. Told them I was through with RI and I've never been back. That was also partly because the room was dirty and nobody cared.