I can't give you a review of where to hold your wedding, only because mine is not until March and I have'nt been there. I can, however offer you some feedback from what I've read from other brides who have had their wedding there. If you're looking for on the beach: you have a few options, the best being Playa Azul, which is a beautiful private location (as private as you can get on the beach) at the far end of the Barcelo complex (beside the Barcelo Maya Beach Hotel). Another Beautiful location is Coral Beach, which is outside the Palace Hotel and located a little above the ocean among beautifully lit Palm trees at night (which is where I'm holding mine). There is also Palmeras (sp?) beach which is outside the Tropical hotel (I think) and is nice, from the pictures I've seen.l But you're also in between the loungers, which I'm sure you can ask them to move. From what I've read, there's also the open air restaurants (don't know their names) that brides have been quite happy with as well. It really all depends on what you're looking for.
Hope this helps,
I know if you look through the thread, there will be some other reviews that will help,