Overall, this was an okay place to stay. We checked in at 2 pm and they said our room was ready (after a bit of hesitation), and then we got to our room to find towels on the floor, no toilet paper, etc. They obviously got it ready eventually, but it just wasn't ready at the specified check-in time. Also FYI--most of the elevators we experienced in Madrid residential areas, including this one, were super tiny...they are only about 3 people wide, 1 person deep.
We stayed in a private double room, and it was nice to have a private bathroom. The room was pretty small, and the bed was better than a futon, but not particularly comfortable. The room had a subtly funky smell that never really went away (we got used to it, but would smell it every time we walked in). Also, the double bed had only 1 pillow (the width of the bed, but kind of awkward to share). There was an A/C unit in the room, but there was no remote control. We had to have the front desk come turn it on/off, but couldn't keep the remote as there were only a few for all the different units throughout the building, and so couldn't really adjust the temperature. Wifi connection cut out a few times, but was great overall (we streamed Netflix without issue).
It's in a great location! It's about a 5 minute walk to the Royal Palace, and < 5 minute walk to the Sol metro station. There are a lot of good restaurants and shops right in the area.