My husband and I arrived in Madrid on an overnight flight from the East Coast of the USA. Check in wasn't till noon but they let us keep our luggage there, which was really accommodating of them. When we came back at noon, our originally intended room wasn't ready but they gave us one that was.
Staff is really nice. Our sheets had stains on them but they were swapped the next day for cleaner sheets, and housekeeping cleaned our room daily and kept it in pretty nice condition.
The room averaged to about $72/night. Really not bad for a hotel right next to Opera, Plaza Mayor, and Puerta del Sol.
Decent amenities. Hair dryer, some toiletries, flat screen TV, free wifi. Drinks from the minibar fridge cost 1.25 Euro.
The bathroom and bathtub are tiny (but then again, I'm used to American hotels).
On the advice of other reviewers, I avoided the breakfast, so I can't speak to the quality of that. But there are a lot of great places to eat nearby (including the famous Chocolatería San Gines).