Porta Nova is a simple, convenient building very close to Sultanahmet square (500m) towards the north and the harbour/ferry station on the south. The room was very spacious, airy and has a great terrace - exactly like the pictures. The tram is about 900m away, but do note that the path is steep uphill and you will have to drag your luggage. This should be mentioned in the listing, ideally.
As for the host - friendly, communicative and helpful. Late check-out was unavailable due to other guests coming in, but the host let me store luggage, come back later to use the kitchen, eat lunch in the dining room, and help with suggestions for getting to the airport. He also helped with my luggage on day 1 (the room is on the 2nd floor and there is no elevator).
The room had a little bit of a damp smellz probably due to an under repair / open AC unit. If that can be fixed, and they can arrange a daily cleaning / turn down service, I would've rated this 5*.