I am a frequent flyer/traveler and God knows how many times I came to Istanbul and stayed in various hotels. I can gladly say this one is the best yet. To prove my point, I originally booked 3 nights, but extended it another 5 nights. Turkish people are known to be very hospitable and this hotel has some of the nicest staff. Mr. Hakan at the front desk was very kind and upon learning my extension to stay, he upgraded my room. Mr. Abdullah (concierge) was also very kind and helpful.
As for the rooms: the first one was a king bed at the 13th floor (yup, this hotel has a 13th floor, they are not afraid of superstitions). Very clean room, with an amazing view of the Mall of Istanbul, the river of traffic flowing around it, showing you the true modern Istanbul.
The second room was a 1 bedroom, 1 living room residence at the 28th floor, which has a very good size kitchen. Perfect for a couple.