It wasn't my first time in Istanbul and I have to say this appartment was the best one for staying.
I got very quick and detailed replies from Emin for all my questions. Emin and his friend are very welcoming, hospitable and helpful people! (I wish you both iyi şanslar)
Location is very suitable for Taksim and Beyoglu area (I read in previous review it was difficult to find - amen I say unto you it is not true - if you have google maps and not huge suitcase - it will take 7-10 minutes from Taksim to find it). There is a very good ventilation system in the bathroom (what is rare for this area because the houses are not new), there is an excellent heating system and constant hot water in bathroom and in kitchen (what is very important in Istanbul in winter), there are very well working cooking top, all kitchen equipment and even grill!!! The bed is very-very comfortable.
You can find 24/7 grocery stores around where you can find everything you need (turkish coffee or strawberry in January for example).
The area is safety - a couple of times we (two girls) got back after midnight and had nothing to fear. On the way from appartment to Istiklal (which takes 10 minutes max) you will meet the amazing view on the Golden Horn, so the walks from home and back are unalloyed pleasure.

Once again I would like to thank Emin and his warmly welcoming city!
Iyi ki siz varsiniz!