I stayed over a month in Irina's studio and I had a great experience.
Fully equipped, super comfy double bed, fast WiFi, plus a nice and classy "vibe". I also loved the location, super close to both Chueca and Malasaña while still being on a quieter street.
Communication with Irina was always smooth and fast and she got out of her way to assist me when necessary. For instance, I had a problem with the washing machine that she took care of without delay.
One minor thing: at times you will hear the neighbor's TV or loud conversations (which did not happen very often in my case and when it did it was always at a normal hour).
I would definitely stay there again and I encourage anyone looking for a central and cozy location to explore Madrid to book this place without hesitation! Thanks for everything, Irina.