We had an great stay at Damir's place. It looks exactly like in the pictures and it's spacious and clean. It's also conveniently located close to the bar and restaurant area and the shopping mile.
Damir is a really friendly host. He did everything to make sure I find his place. He called me after my arrival, offered to talk to the taxi driver and awaited on the street in front of the apartment. There is also a 24h hour shop to the left of the building entrance which is very convenient (note that they stop selling alcohol after certain hours, though). I would recommend Damir's penthouse apartment to anyone traveling to Istanbul.