My wife and I took a short trip across the pond to Madrid. We stayed 3 nights at the AC Santo Mauro. Lovely property. This was paid with points, about 120K for 3 nights.
The only minus was the location, about a 10 Euro cab ride to the fun parts of town. Maybe a half hour to 45 minute walk if one were so inclined, though the streets are pretty busy. There is also a metro stop a couple blocks away and that is nice as well, though we ended up cabbing it for the most part.
The property itself if very classic, lovely lobby, restaurant and bar area. The front desk and concierge were quite accommodating. We arrived on the red-eye so it was 11 am. They informed us that a suite was saved as an upgrade but wouldn't be ready for a few hours. So we left our bags with the bell captain and explored.
There is no concierge lounge, and we were offered points or free breakfast, and took the latter. Being Europe it is not a traditional breakfast but still quite satisfying. The room was large and well appointed.
The wifi was strong, but limited to three devices. I have three myself and my wife two. So I talked to the front desk and they gave me a second key/password to use.
We did walk down to the Westin, it was quite nice but really a traditional hotel. It was formal but without a lot of personality. The location of the Westin is near the Ritz and closer to downtown, walk-able to a number of areas you would want to visit.
Anyway for anyone heading to Madrid, I strongly suggest the Santo Mauro