Location, cleanliness, accuracy, being the local guide, comfortable bed, pillows, linen to bathing things, all awesome. This has to be the first place visiting Istanb, Marina and Jihad both will give you the best guide to entire istanbul from cafes, places to visit, local public flavors, information on getting around and to other cities, they are all what you need for Turkey 101. Also, I would always prefer staying in Besiktas, its calmer, smoother, less crowded, good people around and you get to see the life of upper middle class Istanbul elites. Leave Cihangir, Taksim, Fatih, SultanAhmet, try living away from the Tourists and get to fuse and melt with the locals.