We spent three weeks at Maria's apartment (though our contact was through Juan the entire time). There are some great things about this apartment, and some that are a bit lacking.
First the good; the apartment is in a fantastic location just north of the Setas. It's enough out of the main tourist area, but with plenty of great amenities nearby, and a short walk to all you'll want to see. We found this a perfect balance for our stay. The apartment itself is spacious, the shower pressure is good, and the bed is comfortable, if on the firmer side. Juan was also a fantastic person to coordinate our stay. He was timely in all his replies, would drop off extra sheets, and even stayed to fix the toilet when a piece broke. Communication was always easy.
On the not great side of things, several of the apartment's amenities were not up to par. Many of the kitchen utensils were very old and in need of replacement; a broken and splintered cutting board, Teflon pans torn and peeling, and in total lacking a few basic items. In the bedroom, the pillows and bedding were very subpar. We had to go out to Zara Home and pick up a few things to replace them. Some we left, some we took with us to our next location. Lastly, we booked the apartment because we were told it would be very quiet. While it's completely insulated from street noise (this is great), the inner courtyard life can be loud at times. Like when a woman's dog would bark for hours, or the kids returned from school and played football in the courtyard, or the couple on the other side of the wall would argue. You're privy to all these sounds. If the person below was smoking a cigarette, the apartment would smell of smoke. Some of these things may be part of the charming community of the building, but at times they could be annoying on our longer stay. If you're happy to embrace the local lifestyle it shouldn't be a problem, but if you need a peaceful retreat this might not be it. Overall we still found it to be a good home base for us, but with a few updates to the apartment it would be far more ideal, and in balance with the friendliness of our hosts.