but the first one on the list (Atlantico) is not a BW, so one the 7 BW hotels that the BW site lists is missing. But of the remaining 6, most seem to be smilarly rated, and note that the review ranking is not the same as the review rating, so I suggest you just look at each one individually. Most seem to be of good enough qualiity that you just need to focus on your particular needs (including perhaps location and/or price).
I've stayed in two BWs in Madrid the past six months.
HOTEL CARLOS V
Pros: Very centrally located -- the heart of Madrid, a few steps away from Puerta del Sol (where the protests are staged!), and close to/across street from El Corte Ingles (huge department store, including a well-stocked supermarket at the basement) and fnac (electronics, DVDs, books, etc). Also walking distance to Plaza Callao (restaurants, metro stop, shops) and the Opera. About 15-20 minute walk to the Prado and other museums. A delightful bar/breakfast area (2nd floor), with balconies overlooking the vibrant, busy streets below. Two-for-one drink specials during happy hour.
Cons: Tiny rooms/bathrooms, but clean. The area can be noisy/too busy for some. (I didn't mind it at all.)
Pros: Also very central, but closer to Gran Via, a major shopping street. But only about 50+ meters to El Corte Ingles, fnac, Puerta del Sol, Callao, etc. Rooms/bathrooms are much larger here than at Carlos V. The breakfast has an Asian/Japanese section (i.e., rice and miso soup). Free cava (sparkling wine) during happy hour.
Cons: The facade is still undergoing renovation, but hopefully will be done soon. There is an amusing, strangely shaped (triangular?), really tiny elevator that has to be seen to be believed. I found it "charming" but many others were complaining about how it managed to fit only 1-2 pax, without luggage!
My recommendation: Hotel AROSA. Better value for money, IMHO. Also saw the Hotel Mayorazgo, which is also close to Gran Via, but towards Plaza Espana direction. The Mayorazgo is convenient to one of the major tour operators, perhaps a factor if you are taking many out-of-town tours. But did not stay there/see the inside of hotel.