My wife and I stayed at these locations during our week vacation in Spain.
Here are some comments: Hotel Mora
, Madrid: perfect location for us, right across the street from the Prado and a short walk to Parque del Retiro; close to Atocha station and metro stop; very clean and the front desk was quite helpful confirming flights and other arrangements; priced right for us -- about 75E; even though it's on a busy roadway, the windows are double sealed and we could not hear much traffic or noise from outside, if any - our room was an outside room overlooking Pl. del Prado; would definitely recommend Hotel Mora and would stay here again. Hostal Opera
, Barcelona: perfect location for us, just a few minutes from Liceu metro stop; quite inexpensive, 58E; this was our first stay in a hostal; Hostal Opera located on a pretty busy alley way type street; our room was quite noisy during the night but I believe there are quieter rooms if you can get them; front desk not very helpful with confirming reservations, etc. but again this is a hostal and not a hotel with a concierge; a 1 minute walk to the Ramblas was great; very easy to get around the city using the metro from Liceu; also liked being close to La Boqueria, the Gothic area, and the Mediterranean; would probably stay here again if we go back to Barcelona.
Hope this is helpful.