Müge & Nebi were excellent hosts, we rented their flat for a week (4 people). Communication was smooth, Müge sent us a small guide she wrote so we had no problems with finding the house or picking up the keys.
We were in touch with Müge & Nebi during our stay and they were very helpful and responsive.
The flat itself is not very modern (apart from the bathroom), but very clean and well equipped. There are few shops on the same street, open until late hours (including one with alcohol). There's a mosque on the opposite side of the street so you can clearly hear the call for prayers at 5 am in one of the bedrooms, on the other hand - it's a part of Istanbul's atmosphere so we didn't mind.
The streets surrounding the flat, very picturesque during the day are not really welcoming at night, so while walking back home I recommend picking a route through main streets.