We enjoyed our stay. The location is top notch and within easy walking distance to all of the old city. St. Nicholas Plaza is less than two minutes away and has amazing places to sit and eat, drink and watch sport (we were there during the World Cup).
This apartment will not be for everyone though. The ceilings throughout are very low. I am 5-10 and my head touched the ceiling in the bedroom and I had to stoop to stand in the shower. The bedroom is lofted and accessible via an extremely steep and extremely narrow staircase, so people with mobility issues may want to look elsewhere. The neighborhood is home to a number of friendly cats an occasionally we could smell cat pee. It wasn't a huge problem for us, but someone more sensitive might be affected more than us.