OH MY! Joe and I went over the summer for vacation, to Riviera Maya and loved it. We went to Xel-ha and LOVED it. I wish I would have known about it earlier in the week b/c one day wasn't enough. It's awesome, they have snorkling, live parrots just hanging out, lil outside restaurant/bars, shops, hammocks, dolphins! We went snorkling and the water was perfect, it was great, I can't rave enough. It's great. I have not heard anything about Xcarat but I'm sure it's great too, and very similar. DEF try to make a day trip or two there. Depending on how far it is from your hotel, I'd suggest just getting a cab. They hae buses BUT the bus stops at other hotels and picks up people so it can take an hour or more to get there verses 20 minutes... got me? Oh have FUN!