I just wanted to add a couple of more options to stay downtown where you don't need a car.
Matan Ka an is a very nice "la tortuga style" Italian hotel that just opened it has a beautiful pool and rooms and amenities look great, they have good water pressure which is hard to get in other places
Matan Ka' an
Here is Andrea who also operates 40 cañones and some pics of the new hotel
Another option is of course 40 cañones which has a beautiful beach and a good restaurant, the management of this hotels are excellent people and have very nice hotels
I am trying to put together pictures and menus of restaurants for the Costa Maya here, but so far I´m just starting and have this on my photobucket