I love DR for laid back vacations, but you do have to travel around to find decent diving. If you are diving Catalina Island that is a good, but very busy site, ask also to dive Catalinita island which is in the vicinity.
It's pretty well known that I like all inclusive vacations and the DR is the king of AI's. The beaches are spectacular there and the water is beautiful. One thing to watch out for, the tap water is really, really bad there. Be sure not to even let any get in your mouth when your are showering. And if any of you tend to get stomach problems easily, you may want to stay away from the fresh salads and stick to well cooked food, and be sure to pack some meds.
The AI's will have an orientation where they basically try to sell you day trips-tours, cruises, deep sea fishing, etc. I don't usually bother with them, I just dive in the morning and read a good book on the beach while sipping a blender drink.
Oh, another thing is to go claim a spot on the beach or the pool early in the morning. The good, shady spots go fast.
There is a TR on Awoosh.com I wrote a long time ago about the DR, and DocV has another one out there from the DR, both have some good info I think.
Doc, where is your DR TR now?