Great place: super-cental, within short-reach by delivery couriers + there are 24/7 convenience stores nearby, fast and stable wifi, cozy, stylish, clean. Handan and Onur are very responsive and quick to resolve any issues.
Minor downsides are the absence of a microwave and that the floors in the living room and bedroom prrovide weak sound-proofing, so you often find yourself either having to step accurately not to disturb neighbours from downstairs or hearing neighbours upstairs speaking loudly.
All-in-all the place is definitely worth the money and is a great option if you want to stay in Istanbul's citycenter.