Best place you can find in Istanbul !
Erdem, is à very good guy always available if you need some help, the communication is very easy.
The house is very beautiful, and cosy.
The location is perfect you can do many things just by foot (galata tower/ istiqlal street until Taksim/ cross the bridge to go grand bazar)
You can find Metro and tramway around the house (2min)
We spent 1 week (5 adults 2 childrens) everything was perfect, there is a public garden for kids at 500m.
I recomand this house and Erdem.
If you want to discover Istanbul you should go there, if you already know Istanbul, you should also go to Erdem's house.