This is one of my favorites resorts (I'd been there more than 10 times). always stay at Iberostar Bavaro, which the 5 star of the 3 resorts. rooms are all suites, well decorated and very large. Dominicana and Punta Cana are 5 story buildings. I think they have standard rooms.
As other say, there is not more than good things to say about iberostar.
Food is from good to excellent. there is more than 10 restaurants to choice.
Night life is also great. you have the disco D-6, which is great for youngs. the are bars all over the resort. but i dont remember to see a swim bar. I am not too much into swimming pool. the beach is just to amazing to go to the pool.
there is also a good dance club in RIU, next to iberostar, PACHA, this club is even better.
have fun