It's my second time in Kerem's place and I have no doubt I will be back there whenever I come to Istanbul.
The place itself is in a colorful and nice street very close to Taksim Square (which means you are very close to all the public transportation and everything the city has to offer), and quite calm and quiet as well (which means you can have a rest after a long day). The room is very convenient with all the amenities one needs for a short to medium-term stay. It's very clean and cozy.
Kerem and Murat were very hospitable, helpful and welcoming. The check-in was extremely easy and there was always someone in the entrance floor to help or greet you.
All in all, a very nice experience. Highly recommended.