We stayed at Villas de Rosa, really south of Akumal proper, but we made the $5 taxi to Akumal to eat a few times. Villas de Rosa was beautiful, with open balconies, large living/sitting rooms, complete kitchens... the weather was wonderful, so we didn't need air conditioning at all (it was available in the bedrooms should it be needed).
Villas de Rosa caters mainly to cavers, and their open water boat is small and slow - but there are plenty of good sites very close by, and Tito (DM) and Fausto (boat driver & crew) were friendly, accomodating and anxious to make every dive a good one.
The sites are varied - you can pretty much dictate anything you want... as I had several youngsters in my group, we wanted shallow sites, and were gratified to find there were plenty of good ones - so we were able to make 50 - 60 minute dives the norm, with plenty of natural light to keep things colorful.
Lots of turtles, a few nurse sharks and Barracuda, the usual tropical mob - the occasional *huge* rainbow or blue parrot, a few big rays... the kids had a blast so it was a very successful trip.
Where are you staying? My Bride ("Scuba Mom") checked out several of the other facilities with an eye toward repeat trips to the area, so perhaps we can provide a little advance info.
Rick