The Alpek Hotel's location is fantastic and breakfasts are amazing looking out over the Golden Horn and Bosporus with beautiful ancient buildings all around and ships moving on beautiful blue water. Yes, the rooms are small, but they are clean and staff are great.
If you plan on spending your days in Istanbul in the hotel pool and lounging in your room, you had may as well not go to Istanbul, but if you plan on actually seeing one of the most amazing cities in the world, the Alpek is a great place to say. I've visited Istanbul many times and have tried other hotels, but once I hit on the Alpek Hotel, I've been coming back to it every time that I can. There is no better place to experience all that is fantastic about Istanbul.