Fantastic apartment in a calm area that's very well-located, if you're looking to be in a trendy, artistic, kind of up-scale neighborhood in Istanbul.
The rooms are spacious, beds are comfortable, and the flat just feels really good overall. Also, the building is tucked away just enough to avoid street noise. You will most likely get a good night's sleep here.
One thing to note for those who aren't particularly athletic or just generally fit is that often to reach other venues in the area or nearby, you'd need to work your legs a little, as Istanbul (Beyoglu in particular) is famous for its steep streets. But it's nothing that will bother you. You get used to it quickly, and - as a plus - it keeps you fit!
Otherwise, Özgür is very nice and attentive. He checked in multiple times to see how our stay was going :) We enjoyed our stay!