We stayed in Pilar's place our last night in Madrid since it was so close to the airport. Contrary to what one of the other reviews says, you can order an Uber to the airport, but you need to walk about a block away from the place (it's barely inside the airport geofence).
Pilar's place is very spacious and had more than enough room for the four of us.
There were two things we didn't like about our stay. First, the door was wide open when we arrived to check in (it was supposed to be locked). This freaked us out a bit, but it sounds like whoever was supposed to close/lock the door rushed on their way out. I think it's unlikely that something like this would happen again. Second, the bathroom is connected to the back porch and doesn't really feel like it's inside and the shower doesn't have hot water. Not a huge deal, but we didn't expect it.
Overall, Pilar's place is solid if you want a good amount of space close to the airport at a great price!