The place is neutrally good, but taking into account the price is 5/5.
Really cool features:
1) location (5 min to the historical center) - perfect for the first visit to Istanbul
2) wide balcony with authentic view
Neutral features:
1) rather clean room, but not so fresh
2) regular religious chanting could be heard, but this should be the thing for all apts near mosques
Thing to be aware of:
1) wi-fi connection merely exists - ok to check the routes or post smth light weighted, but inapplicable for work
2) it is actually 2 split rooms, so you could here the second apt to a certain extent