I went to this restaurant with my friends after I saw the "chefs of the year" article on GQ Turkey and another article about it on the Wall Street Journal's website.
The restaurant is at the hip, newly renovated Akaretler area, which houses a lot of fancy boutique hotels and restaurants. It is a mid-sized restaurant with maybe 5-6 outside tables where you can watch the vivid street scene and a stylish(to my taste, of course) interior seating area.
I must say I'm very impressed with this restaurant. I've eaten at numerous restaurants in Turkey with great food, but this one has an edge. They serve Turkish cuisine but in a very experimental and different way.
It was a breath of fresh air to taste the familiar foods in different shapes and mixes, and in the 'artsy' form they are served. I got the "24hrs" lamb shank, and it was one of the best lamb shank(s) I've eaten in many years. (and the plate look like 'artsy', which was not necessary but welcome :) )
I also recommend you try the watermelon salad if you visit the restaurant..
This is now my top restaurant to take my foreigner friends who are visiting Turkey, to show them how rich is the Turkish (and mediterranean/eastern) cuisine.
In terms of quality & taste of the dishes, I would compare them with Balthazar's in Manhattan.
On a side note, they have a nice selection of wines, but beware - this is not a very cheap restaurant- but it's worth the experience. Also, 1 or 2 tables seemed a bit cramped, so make sure you make reservations early to avoid getting a table with tight moving space..