Right from the beginning, Derin was super responsive. On arrival, we had option to leave the luggage in the next door, which is a hotel managed by Derin.
Derin's house is located in a fantastic location, near to the attractions / transport / bars and restaurants. Under a minute or two, you can step into Istiklal street! Property is on ground floor, given we had multiple luggage, this was a plus point - many other property/hotels don't have lift. Expect little noise on Friday / Saturday nights due to the proximity to the nightlife. It did not matter to us much as the property is well soundproofed.
Derin was super friendly and helpful and advised options with no commercial self-interest, just like a good friend, gave us tips that were very useful.
Bathroom was clean, and so was kitchen, which had sufficient utensils to cook. Good quality washing machine was present and some detergent too.
Happy to recommend or stay again.