Good: the crew, the boat and the drop locations were fantastic! The crew was very friendly and helpful. The snorkel destinations were awesome (except for one jellyfish-filled location, which was remedied immediately). Had one of the best lunches at Gili Air. Fun, fun, fun experience.
Bad: three things: too many people, too many people and too many people! The snorkel locations were so crowded - we counted up to 18 snorkel boats in one tiny area. All the snorkelers were mostly beginners, so we experienced a lot of people grabbing and climbing onto us; kicking and pulling on our snorkel gear. Too many people.