Our family of 3 stayed 3 nights at Quinta do Vale and we thoroughly enjoyed our stay. The Quinta is lovely, located in a residential area with all the amenities of a nice hotel but in a nice family-run inn. Do note that it is located about 10 minutes outside of center of Horta and you need a car to stay at this place. It has a beautiful pool in the back (perfect for kids), sauna, steam room and gym.
We stayed in the Sao Georges room and it was spacious for the 3 of us. They put a rollaway bed for my son, which was perfect. Bed was comfortable and the room was air conditioned, which was very nice. The room was very clean and bathroom was ok with good water pressure. They provided clean beach towels every day for our use. The only minor complaint is the fact that wifi were not working in the lobby while we were there. But there was a LAN connection in our room.
We loved the breakfast. It's continental with bread, different hams, Azorean cheeses, yogurt, cereals, local fruits (pineapples, grapes, etc...) and Azorean cakes (yummy). And wonderful coffee.
For our 3 night stay, we were also given one hour to use the sauna and steam room, which we did take advantage of. Afterwards, we jumped into the pool, which was quite cool. Overall, we really enjoyed our stay and will definitely return.