I was there in early December. It is really a suberb all inclusive dive resort. They do everything right. The resort blows away places like Little Cayman Beach Resort. The bungalows are comfortable and quiet (not like a cheap hotel), they don't blast loud music and bad karekoe to stimulate bar sales, and the food is better. They even walk you through customs.
I'd say the diving is similar to Turks & Caicos, but sligtly better. The coral is a bit healthier (less polution) but all of the elk horn was cut down by Mitch a couple years ago and is just starting to grow back. It has only one spectacular wall--Mary's Place on the south side-- but my sense was that fish were more populous and bigger. We saw turtles, sea horses, sharks, wild porpoises under water, and the bizzarly gregarious eel that lives in the wreck of El Aguilar (what it, he/she does NOT like cameras and will go after them). Most dives were drift dives and for the first few days the seas were running higher than most passport divers were comfortable with (keeping the boats nice and empty for the rest of us!). Also, try the shore dive on the north side of the Key, but skip the night dive in the marina.
I understand that whale shark season is when the water is coolest--Jan. through Mar. (which is why I'll be in Utila in a few weeks).
The water temperature was in the 80s but with a week of repetitive dives I'm more comfortable in a 3m shory or .5m skin. This is a fine place. I'll be back.