PROS:
The location is really good, it's right in the center of Madrid, pretty much walking distance to everything, bars, restaurants, flamenco shows, Mercado San Miguel, Plaza del Sol, etc.
CONS:
Walking almost 100 stairs up to get to the flat is kind of tiring after walking a full day in the city but that's ok, It's in the description.
If you are the kind of person that takes long showers, this is not for you, hot water runs out within 5 to 8 minutes, so you gotta be quick so others can shower too or they will have to wait between 30 to 40 mins for the water to get hot again.
And one last thing, you have to climb up a ladder to get to the bed, if you're the type of person that wakes up in the middle of the night to go to the bathroom, keep this in mind.
Other than that, this place is ok.