We've come to Akumal about once every three or four years and, sadly, the quality of experience has diminished each time we visit. There's just too many people visiting now, and the impact is very noticeable - still nice, but not nearly as nice as it used to be. Akumal is still a good alternative to the party madness of Cancun and Playa Del Carmen though. If you do come, we'd recommend staying away during spring break and Easter week, as that's the busy season - again, too many people!
The road to our condo from the center of town was much busier this time around, loaded with tour buses from the large resorts, and the fragile Yal Ku lagoon has been overrun with snorkelers. The beach all around Half Moon Bay was clogged with huge piles of stinky Sargasso seaweed (we may have delayed our trip if we had known about it) and there was confusion about the limited access to Akumal Bay beach, with associated political issues involving locals, the protected turtle breeding grounds, and beachfront hotel owners. We were unable to leave town one day, as the road was blocked by protesters.
Our room itself has always been okay, a nice clean little room for us to stay, with reasonably good maid service and quick access to the beach. We did have intermittent issues with the internet, but we really didn't depend on it much during our stay. We like Casita Sur because it's lower cost, and it faces away from the beach so it's quiet and private. The property management group, Green Eyes, was helpful, especially for arranging to shuttle us back to the Cancun Airport.