One thing that I find inconvenient is that there is no way to add a name during the booking process if you are doing it on the website. Requires a call to either Marriott or the hotel.
Strange as I do this all the time online. I can't remember the choice but it's something that doesn't totally make sense. Then there is a spot where you can type a little. I add my wife's name there. Never had a problem except the one time I forgot to put her name there.