Location, location, location. It is centrally located to everything. Room is small but very comfortable for 2 and also you want to spend more time outside. Step out and take right where there are numerous bars, restaurants, historical marks, shopping options etc... If you visiting Madrid for the first time then this is the place to stay. Very safe as the street is always crowded even till late night.
I might have missed it but the apartment is on the 4th floor. It is a workout if you traveling heavy (like me) as there is no elevator. Not a deal breaker for me but keep in mind.
2 Minutes walk and you can get Taxis as needed . Host was waiting for me right on check-in time as discussed with prompt communication. Also helped us take our luggage upstairs. Thanks Ruty