I stayed at this apartment for almost 3 weeks, and really enjoyed my stay. Though smaller that what I thought, the apartment is cozy, has strong A/C and Wifi, is very modern, and ideally located on the 7th floor (nice view) near the Plaza de Toro and all the shops. It also has a lot of attention to details, which makes your stay very enjoyable. It also has a washer/dryer, which is very useful.
Given the size of the second bedroom, I'd say this is an ideal apartment for a single person, a couple, or a couple with a child.
The only negatives for me were the quality of the mattress (but I guess this is a personal issue), the very small TV, and the fact that I could not get any package or urgent mail delivered to me at this address. So for longer stays like mine, it is something I wished I could have received help from the owner.
Aside from this, this is a great value apartment, very clean, that anyone will surely enjoy staying at, and that I would recommend.