Hello, Mexicobride!
I feel your pain! I joined this forum simply because of your post. I have so many of the exact same concerns you do! And I know if we have these concerns, there must be others out there who have already been through this and can share some much needed wisdom.
I'm planning on planning a wedding in Playa del Carmen for next November. And after hours of researching hotels, I'm back to where I started (which is the Riu). I really need the help of someone who's done this. Anybody with experience of coordinating about 50 guests would be awesome to hear from!
Or any help in general would great!
Thanks!