Mehmet is a very good host: everything in the apartment was fine and clean. It is big enough to host four people (we were a couple and two friends, but I think it would be perfect even for a family). Heating works very good, the kitchen is new and has everything you need, the bathroom is small but comfortable. The location is wonderful: close to the most lively street of Beyoglu, but absolutely quiet at night.
We definitely recommend Mehmet's flat!