Went to the IHD 2 years ago. We decided that we would do the Saona island trip and the Santo Domingo trip and so plumped for the South rather than the East, where you had to travel across the island to start the trips (an extra 3hrs per trip). Other factors involved were the calmer waters and softer sand.
The North has the strongest waves as it is the Atlantic, the South has the calmest seas as it is the Caribbean, or some such thing.
At the time we went the IHD had the reputation of being one of the best hotels on the island and we enjoyed it, however times change and you may be after something different.
I hesitate to recommend anywhere because a few years back a large group (27) of us had a fantastic holiday in a turkish hotel, but within a couple of weeks many of the subsequent guests at that hotel ended up in hospital, so all I ever say is that I had a great time and it was good when I went.
The weather at the Playa Pesquero end of Cuba is supposed to be better and at less risk to hurricanes. The lad on the Cat snorkelling/dolphin trip told me they had only had one hit in 20 years or so. Don't know if it is true.
It is a lot further to Havana if that is the reason for the trip, but they do run (high priced) 2 day trips to Havana from the hotel.
Forgot to mention the Coffee bar in the PP.
Have a look at the threads and reviews for both hotels. If you go to Cuba try and go eclipse as the first choice planes are better standard class than the others. Thomson planes and FC planes to DR are supposedly the same standard from May this year.
We went to both places in the second half of June and it did rain at both locations but not enough to upset the holiday.
As for the PP which is the last one we went to, if you just want to laze around the pool or the beach there is plenty of opportunity, you can also take bikes from the front of the hotel and ride around the area. you may even see some traffic.
It is a long time since I was 20 so not sure what you would be looking for to keep you going. With us were my 18yr old son, 21 yr old daughter etc and they both would go back. Price wise we paid £750 each last year for the 2 weeks but I can't seem to get it below about £875 this year. Trouble is the TO wants the same price for my 2 yr old, which I baulk at, particularly as I have to pay!