We stayed at Eva and Gloria's place for our 4 day trip to Madrid. It's a bit away from the city center but it's connected by Metro (10 mins walk) and Bus (2-3 mins walk), so if you buy the Madrid tourist card, it shouldn't be a problem.
We really liked the place and Gloria was really helpful. She allowed us to check-in early and also leave our bags after check-out as our flight was at night. She also gave recommendations on places to visit around Madrid.
If you like dogs, you will be greeted by their dog Lima who is an absolute sweetheart! :)
We really enjoyed staying here as everything was very clean and tidy and Gloria was very responsive and helpful. Would definitely recommend this place if you're visiting Madrid.