This was our second year in a row to Half Moon Bay in Akumal, and our first at Luna Azul. We were very happy with our building and second floor unit with private balcony and spectacular views. The spacious living/dining area and separate two bedroom/two bathroom layout comfortably accommodated our two couples. Our unit had a security box; we know another did not, so be sure to ask. Be aware that toilet paper cannot be flushed in the toilets here and at other buildings on Half Moon Bay -- surprisingly, it turned out not to be a big deal. When comparing this building with others, consider whether the 19% Mexican tax is included or not (it is at Luna Azul). Great service by office staff Marcial and Roberto and our cleaning woman, Adela. Weather was absolutely perfect for our 12 days, hovering between 79 and 80 F, day and night, with a nice (and usually strong) wind that resulted in no mosquitoes. For snorkellers, Half Moon Bay is rougher than Akumal Bay in terms of waves and rocky shore (may not great for children), but we were happy with the fish we saw out near the reef, including rays, trunkfish, cowfish, trumpetfish, a school of 250 or more Sailor's Choice, a young turtle, reef squid and a pair of giant rainbow parrotfish. Akumal Bay snorkelling was not as good as it was last year ... very sad. A flipper ban is in effect there to protect the seagrasses, but fins really aren't needed -- you will see sea turtles and various kinds of stingrays there, even in shallow water. Also, snorkelling in Yal-Ku lagoon (with flippers) is highly recommended (at an entrance cost of about US$18, plus any equipment costs). Take biogradable sunscreen with you to Akumal to protect the marine life.
We took a tour to Coba Ruins, just over an hour's drive away, and highly recommend it. It is unique in that it is situated in a shady forest (again, no mosquitoes). We rode bikes within the site to get to the main pyramid, where we also saw extraordinary tropical birds in the forest in a clearing in front of the pyramid, to the left: motmots, trogan, Mexican jays.
What we also love about Half Moon Bay is that a variety of restaurants, snorkelling venues and everything you need are within walking distance (within about a kilometre of Luna Azul). We will return!