I am getting married at CSA in June. We liked that it was Adults only. We chose Negril because the trip is a little closer to MBJ at 90 minutes. I was told that there was a lot of road construction on the way to OR that could cause delays. (I don't know if this is still true, but it was when we booked). CSA is the newer of the Couples resorts, or at least the most recently renovated.
TA Jennifer did a great review, complete with pictures, on CSA.
http://bestdestinationwedding.com/forum/t12426
You can also go to the Couples website, Jamaica Resorts: Couples Resorts - All-Inclusive Resorts: Jamaican and read their message boards. Lots of brides have posted pictures and videos there.
ALso use the search button to read the reviews from the Riu here!
Good luck!