I stayed in Luisa's apartment for just over a week. It was a great experience! My flight was delayed, but after letting Luisa know, her father was able to meet me at the apartment at the new time. It had everything I needed for my stay and was incredibly clean. The wifi worked great as did all the appliances. There was also plenty of hot water. Luisa's father took the time to explain everything to me when I arrived and answered all my questions.
I couldn't have asked for a better location right next the the Chueca metro in the center of town. You can walk anywhere you want to go or take the metro when you're tired of walking. There's also a great supermarket within a 2 minute walk! For getting a taxi back to the airport or for anytime you're not wanting to walk or take the metro, I recommend downloading the "Mytaxi" app. With it, I was able to get a taxi outside the front door in less than 3 minutes every time. As a heads up, it's a flat rate of €30 to and from the airport.
The only item you might want to be aware of is that it's a central location that is very lively. The street is quite noisy at night on Friday and Saturday. You can hear it with the windows closed. It didn't bother me, but if you're a light sleeper, it might get annoying.
I absolutely recommend this apartment to anyone going to Madrid!