Hey glimmertwins,
we haven't been to Grand Cayman since April 2005 but I still remember the dives. Stayed at The Reef on the east end and did our diving with Ocean Frontiers. The condo at the Reef was fantastic. Very nice property with several pools. Nice easy snorkeling off the beach, but no shore diving on this side of the island. Loved the staff at Ocean Frontiers. Thought the cost of our four dives was to expensive though ($400+ per person), but the Cayman's are expensive over all. The did give use a couple of free tanks so we could get in the resort's pool and make sure our equipment was okay. Had a malfunction with our dive computer and they fixed it for free (minus the cost for the part).
The diving on the east end was not to difficult. This was only our second dive vacation and dives 16-19 for both of us. Deep canyon walls, lots of the usual fish, nice corals, and big Tarpon. We would do it again if the price was right, but not our favorite destination.
Stayed at Sunset House on the west side our second week. The room wasn't as good here, but the property was still pretty nice. We only did shore dives here on their house reef and it was fantastic. Saw multiple turtles on every dive as well as several eels, nurse shark, stingrays, the usual tropical fish, grouper, very friendly Angelfish, nice mixture of sand patched and coral gardens. They even have a small landing craft that was sunk. Worth a shore dive if you get that way and have the time. The best part was the 5 dives there cost under $100 for both of us.
Hope you have a great time!