It's a great place to base out of to explore Kadikoy (and very close to the ferries, so the European part of Istanbul is also very reachable). It's spacious, the heating was spot on for the wintery temperatures, kitchen is very functional, as is the bathroom.
The street outside is somewhat lively till late, so if you are a light sleeper and end up in the street-facing bedroom, maybe some earplugs will help.