Great place and even greater host !
The room is big and comfortable, the bathroom has everything you need and the big living room is a great hangout-spot...
Combine this with a host who tends to your every need and has tons of advice if you ask for it and you have yourself a five star airbnb location!
The only minor setback is the distance to the old town. The area is very good and has tons of shopping opportunities and easy, close access to Taksim, but you have to take 3 very short tram/metro rides to get to the old center. And since you can't transfer from one line to another for free (with reduction though thanks to Esen's Istanbul kart), we ended up walking to and from Kabatas. But if you don't like taking a short walk with some height difference, you shouldn't be city tripping and especially not in Istanbul. So this is only minor nitpicking and didn't bother us.
All in all 99/100...