I have looked at going to th DR many times, what always gets me is the mixed reviews. On top of the long flight times ( changes planes,ect) I have alwasy choosen not to go. I travel quite a bit for work and dont' like spending a full day of vacation traveling. I have been a few riu resorts int the past, and none of them have been that great. the only all inclusive resorts I will stay at are the Karisma resorts in Mexico.
http://www.karismahotels.com/
My wife and I go once a year ( at a min). we're going back down this wed. This is one of our favarite vacation spots to relax at. The price is hard to beat. for the last 3 years we pay approx $2k for 4 nites , 5 days, airfare and roundtrip limo transfers.
It's an easy 1.5 hour flight too