Stayed at the Santo Domingo Hilton in Washington Avenue for 2 nights during a business related travel in Oct 2012. It was my first time in Santo Domingo. This is a high class hotel with high speed panoramic view elevators (a soft spot for me), and it gives you a good vibe from the start.
The service. The staff is really friendly. No contest when compared to Marriott and others, I felt welcome and this is what hotel service is supposed to be.
The room had a ocean view, which didn't mean much since I arrived a couple of days after tropical storm Sandy had its way with the area. The rooms are spacious, well maintained with big beds and a 37 inch LG LCD. Every day room service leaves you 2 bottles of mineral water free of charge. The room also has a 4 digit safe, big enough to fit most laptops or tablets.
The food. Tried the breakfast buffets. Lots of options and a special area for low-calories. This was a weak spot, since on my second day, don't know if maybe it was too late or what but the staff failed to bring me coffee (after asking) and my table didn't have napkins. There's also a lounge on the 20th floor that has a big aquarium, a couple of big screen LCDs and free Wi-Fi. Also lots of snacks and beverages and this is included in the hotel fare. Went there to relax, enjoy the view, eat some snacks and browse the web. Great!
Also tried the gym, which has 5 treadmills and other machines, is a medium area with TV and is open 24 hrs. Didn't get to use the swimming pool.
In general, i would recommend this hotel for any business related activity. Not so sure about family vacation, since it seemed to me its focus is more geared towards meetings and the like.
Just one tip, unrelated to the hotel, watch out with Santo Domingo Americas Airport (SDQ), after departure and arriving at my destination, found my luggage was opened, the lock bent with a hammer (a TSA combination lock) and the zippers were messed up. Everything inside was spilled and a small hard drive was stolen. Went to the airline customer service (Insel Air). Another passenger on line with me complained that a perfume bottle was missing from his bag. It seems this happens often at this airport so I would suggest carry-on luggage.