I just returned from diving in the Dominican, i was staying in Bavaro near Punta Cana. I dove for a few days with Sea Pro divers off the Punta Cana coast and to be honest was rather disappointed; minimal sea life and a reef in poor condition, also did a wrech dive of a partially submerged freighter which has been pretty well torn apart and was actually rather dangerous for my skill level considering the currents where particularily strong.
I did however rent a suv and went over to the other side of the island where i thoroughly enjoyed the diving. Spent two days diving the wall and reef near Catalina Island; the wall was amazing and i enjoyed the reef as well however less so. Then we spent another two days diving Bayahibe the wreck St. George was really cool, maybe more so for me because i have limited wreck dives however it was big and intact and being able to see where the last hurricane moved her was pretty cool. The reef dives where better than the other side of the island for sure.
So i guess my opinion would be to dive the Bayahibe area as well as Catalina Island, it would be all i did if i went again which due to my wife being bitten by bed bugs and getting sick isn't likely to happen anytime soon.