I have had great service through the years from staff, managers, and the Concierge. In the events, I have written a letter to "Mr. Marriott" -- there is an office that handles all of his email, mail and phone calls. I also "CC'd" the hotel manager.

I have gotten replies both from headquarters and the local hotel. In one event, the reply stated that my letter was one of the reasons that the Front Desk manager was being given her own hotel.