We visited as a family for 3 days around Christmas time. We had a fantastic time in Madrid. The hotel is great. The rooms are large, very well appointed, with lot's of light and quiet. The common rooms of the hotel are very comfortable, never very busy, and great for a short burst of work (if needed). The staff is remarkably helpful and always with a smile. The gym is at the basement -- very functional, but not crowded.
The hotel is situated in the Salamanca area, a great part of the city, with many shops, restaurants, cafes in close walking distance; and the museums in 15min walk away. The hotel is on a quiet street, so it is not affected by the activity one block away.
Overall a great experience, both as a family and as a couple.