I had a great 4 days staying at Kardelen's place. The location is perfect, walking distance from İstiklal and the ferries at Karaköy, and the apartment is thoughtfully decorated and very comfortable. I appreciated the self check-in feature in particular, which made it so easy to move in late at night even without a Turkish cell phone. Kardelen was kind and responsive via Airbnb messenger. I definitely recommend this place to other travelers.