Nacho and Marta's place was ideal for me and I spent nearly 2 months there. I like to have access to the main attractions, like the Prado and the parks, but I do NOT like being hit by waves of tourists or living among them. (I.e.Plaza del Sol is NOT my cup of tea.)The neighborhood, metro Chueca in Justicia, was perfect. It's a charming and sort of hip residential neighborhood. I found an art school close by for drawing classes. There are very good bakeries around and a couple of large indoor markets with meat, cheese and veg stalls. Literally anything you need is a short 5-10 minute walk away. As is the metro stop Chueca on the #5 line. Two of the big shopping streets, Hortaleza and Fuencarral, are a short walk.
The apartment itself was great, bright and cheerful. I need lots of quiet and their place is on the top floor. They also have a super nice terrace which I didn't get to use much because it was still cold in Madrid. The place is furnished comfortably and has all the basics you could need. Comfy bed. They have also put together a little neighborhood helpful hints in a booklet form for guests.
Marta and Nacho could not have been nicer as was their manager Lola. When I return to Madrid I would love to stay there again.