I really like the location in the middle of the Chueca district with all its bars, coffee shops, bakeries, boutiques, etc. The apartment was exactly like in the pictures, there's a lot of space considering I live alone. Furniture and equipment were new. A large wardrobe, fridge, bathroom, and a big screen TV were a big plus. Check-in and check-out were fast. Ana always replied promptly.
One thing I should really keep in mind while choosing this apartment. It is located in the basement of an old building which is evident when you look at the pictures. So there're no proper windows and natural light. It has its benefits and some disadvantages. A major benefit is that the temperature is naturally cool which is important if you stay during the hot season which is quite long in Madrid. The main disadvantage except the lack of natural light is humidity. It takes more than a day for laundry to get dry and a piece of paper left on the table became somewhat wet overnight. I'm sure all of that won't be a big problem for a short stay (I stayed there for five nights and that was ok for me) but if you stay for more than a week I think that could be annoying.
Please don't consider my feedback as negative, I was really happy and comfortable staying there. All the things mentioned above are for you to make a conscious decision and not be disappointed.