Elsa's flat was the perfect place to call home for our five days in Madrid. The place is located conveniently between two Metro stations and is very walkable to areas like Cava Baja and Plaza Mayor. Having a chiller or air conditioner was a big plus as it got over 100° more than once. Laundry was also a big plus. There's a cute little bar next door that is open later, the bartender is nice and the food is pretty good. The street was quieter and the building very quiet, but the area itself is quite lively with lots of good restaurants. Elsa also provided a lot of great suggestions for places to eat and drink in the area.
The only issues with mentioning are two. First, we didn't meet Elsa (she was travelling, but very responsive) and had issues with both locks. The flat door can be locked 4 times by continually turning it; we didn't know and thought we got locked in until we figured it out. The building door needs servicing, the lock was extremely difficult to open and our greeter couldn't even do it. It was difficult every time we used it. Second, if you're a light sensitive sleeper, like my boyfriend, the hall lights are on a timer and used when people come in and out; there aren't heavy shades on the bedroom window blocking out light.