We found it easier to keep our gift cards in the safe and charge everything to the room. A couple days before we checked out (and they processed our credit card) we go to the front desk with all our gift cards and cash to settle up.
We used them for a couple of meals that weren't covered with the DDP & it was great. If they make any more changes to the regular dining plan, I'll think I'll skip it and just use the gift cards.