I used them for my son's birthday. One thing to note is that whatever you plan, it won't be for the day you check in. They make you do it for the day after check in. I'm guessing this is just in case you change rooms, get upgraded, etc.
I will say it was great though. My son loved it. They arrange a time window where you'll need to be out of the room & they set up. They decorate with exactly what is listed on their site. My only wish is that they would have more birthday options, or maybe customizable ones. It was expensive but worth it for a once in a blue moon treat.
Have fun!