Marta and Paul's apartment is beautiful and is exactly as it appears in the photos. I was traveling with my mother and 2 aunts (all over 80 years old) so the location is ideal, with easy walking to many major sights. We walked only 5 minutes to catch the tourist buses. There is plenty of dining, drinking and shopping options close by. The grocery store on the lower level of El Corte Ingles is very convenient ( with more options and much less expensive than the 24 hour markets near by)
We were initially a bit concerned about the street noise as we had the windows open, but once the windows were closed they were very soundproof, so our concern was for not.
I would recommend Marta and Paul's apartment for anyone traveling with 4 -6 people. And I hope to stay there again the next time I have family visiting.