Derins apartment was on the ground floor in a happening street a minute away from Istiklal. All public transport, pubs, money exchange, grocery, restaurants were within a 3 min walk.
However being at the ground floor next to a party street can mean it gets a bit loud at night on weekends. We didn't have an issue but some light sleepers might.
The apartment was well equipped and as per photos & amenities.
Derin was a very accessible host throughout the trip. He helped with the check in, late check out, airport transfers & local tips as well.
His Guidebook was on point wherever we tried it.
All in all, recommend it to two people looking for a stay at Beyoglu and enjoy what the area offers.