Good choice! I think you will be delighted with Aqua Safari. It's being the oldest dive op on the island says a lot. The concern for safety is demonstrated in many ways, particularly their signature two dm's in the water -- the guide in front and the 'safety' in the back. This gives divers a lot of flexibility, as slower observing/investigating divers are not pushed to keep up with those that flow with the current. Aqua Safari matches the needs of both types of divers very well. Plus, the crew are courteous, well informed, give good briefings, and conscientiously act as another check-of-gear before you giant stride. Snacks between dives are tasty, too! While you are waiting on the dock to board the Aqua Safari boat at your Palace Resort, say hello to Bill Horn, the tall, lanky good natured and highly knowledgeable owner -- he'll be there!
As you can tell, I'm a devotee of Aqua Safari, and have done many dives with them over the years. I've also done my PADI advanced courses with them, including Rescue. They have a cadre of excellent instructors; I've done all my work with Gabriel.