Fantastic location - right by the Galata Tower (Galata Kulesi), which is a major landmark everyone knows. That makes getting back there from anywhere easy. Also, more importantly, it's right in the middle of some great neighborhoods.
Karakoy is cool for low key cafes while Istiklal has big commercial shops and a lively bar scene down the back streets... but I don't need to elaborate because Kadir will tell you all about it.
We thoroughly enjoyed our time and would recommend it highly. Probably the only qualification to that I would say is that it's up more than a couple floors and there is no elevator so some climbing is involved; totally worth it!