We had a very nice stay at Meltem house and it's just a pity we needed to leave earlier than planned.
The view is definitely amazing, the location awesome, even though it's climby (be prepared to do your gym) that's a part of Cihangir experience. Very close to the boats and the Dolbamahce palace, and nice cafés and restaurants (Erdinç will give you really good addresses)
Still the flat is very small (I would rather recommend it to two people or a couple, not more) and be prepared to wake up early because the blackout curtains don't do the job. But it's very common in Turkey, so I would say y that's part of the experience too and there is so much to do in the city!