I recently booked two rooms at the same hotel for myself and a cousin. I used an e-certificate to pay for one, and guaranteed the other one to my Marriott credit card. When I checked in, I told the clerk I would want to use gift cards rather than have them automatically charge my card prior to sliding the portfolio under the door the next morning, and they said no problem, just bring them down when I'm ready to check out. At checkout time I handed them 4-5 different Marriott Gift Cards & Travel cards varyinig from $50-75-100-125 each. It took the clerk less than five minutes to process all of them, and that was that. No problems.

HTH.