The place itself is fine - basically furnished by IKEA. We stayed in the 2 bedroom 2 bath apartment and had a kitchenette with a small stove/range and washer. The biggest qualm I had with this place was upon arrival - waiting in front of the building with my kids and all my luggage for the manager dude to get there. They emailed me in advance to ask when my arrival time would be and I emailed them back with the time. Despite this, when we got there, no one was there. We had no cell since we'd just arrived, and had to run around in the streets looking for a working pay phone. Several phone calls later, we FINALLY reached the manager who said, "oh well we arent open yet." It might've been nice if he'd emailed me back to let me know that they wouldnt be open at my arrival time. Instead, we had no idea if he was located inside the building or what, so we basically pushed all the buttons on the security box and woke everyone up trying to find him. He finally showed up to take care of the paper work, etc., but the place wasn't cleaned yet so we had to wait while it was being cleaned. My kids were driving me CRAZY at this point and I too was exhausted from the plane ride, but regardless, out into the Madrid streets we go, looking for a place to get a coffee/waste time while the room was being cleaned.
Our stay was fine after we finally got in. We later saw other people waiting outside for the manager - so be aware that you will have to wait for him whenever he feels like getting there.
Unfortunately there aren't a lot of hotels in Madrid that can accommodate a family of 4 in one room, so we were stuck with this place. Also, this apt is located about 1/2-1 mile outside the main historical center. What's good is that you can get a decent night's sleep. What sucks is that its a long ---- walk with your complaining kids to the main area. Luckily there's lots of cabs around.
For you American families - yes there is a washer but NO DRYER! Apparently everyone in Spain hangs their clothes out to dry!