The apartment is perfectly located: extremely central (1 minute walk from Galata Tower) yet on a small, quiet street. It is very spacious, with a small living room, a decent bedroom, and a small room that can be used as an office. The kitchen is small yet well-equipped, and the bathroom is spacious. The apartment is on the ground floor but is perfectly safe.
We did not meet our host (self check-in and check-out), but communication was splendid, very fast and very efficient. The instructions were clear and we had no problem whatsoever.
One thing to bear in mind: there's a little mosque just in front of the bedroom, so expect very loud wakeup calls for the first prayer of the day... Other than that, the place is very quiet in spite of its central location.