We were just there at the Miami Airport Hilton Friday night and had a similar experience! On check-in I mentioned to the clerk that I needed to switch from a king bed room to a room with two beds because "mi suegra" (my mother-in-law) joined us on vacation at the last minute. She said she'd do one better and give me a nice corner suite so we could have more room. Vouchers for full breakfast offered w/o prompting.