We dove with Adrian of "Dive Home" earlier this month. It is a small, personal operation - I emailed him my desired itinerary in advance and he made it happen. We dove twice on the reef and in two different cenotes; all dives were very nice and had extended bottom times as we were the only ones diving. We wanted something different from Cozumel this year and certainly got it - huge schools of fish and beautiful, vibrant reefs. The cenotes were such a neat experience too, it's like diving through Carlsbad Caverns.
As for Adrian, he's the best dive guide I've ever had in my 20+ years of diving. Full service and a friendly passion for anything scuba, and - assuming you're competent underwater - lets you just enjoy the dive.
Puerto Morelos itself was a wonderful experience, it's a small village with everything in walking distance - the opposite of the 24-hour nonstop Cancun all-inclusive tourist trap. Imagine diving all morning, getting some lunch, hanging out by the hotel pool, having a quiet street taco dinner and finishing the day on a bench in the town square with a view on the water as the sun sets, ice cream cone in hand.
Bonus: I spent the equivalent of $350 for all food and drinks for two people for an entire week! I will definitely return to this hidden gem.