The room was very nice and comfortable and matched photos and description on air bnb. On Sundays, there is a fresh fruit and vegetable market in the street adjacent to the apartment building (which was an added bonus). The apartment is located 10 mins walk from the main shopping and restaurant area in the Beyoğlu district (Istiklal Street).
If you are arriving back at the apartment after sundown, be aware that the building is based a few blocks off a main street and the area isn't well lit (with street lights). I did feel a bit unsafe at times coming home after midnight.
The hosts (Guner & Guven) replied to my emails promptly and were able to accommodate my earlier than expected arrival in Istanbul when my plans changed last minute. The light in the bathroom was broken during my 5 night stay and it wasn't fixed even after I had flagged it with them.