Istanbul is an incredible city, a mixture of oriental tradition and modernity. I was able to discover this during a short stay in early April 2015 in the Turkish economic lung. As far as hotels are concerned, few choices are available and affordable at Starwood.
The only viable choice was therefore the W Hotel, a chain whose modern room design I appreciate, but less so the supposedly relaxed service, which sometimes turns into unacceptable nonchalance in a 5 star establishment at a very high price level.
I booked this hotel through SPG, and used the Best Rate Guarantee, after finding a much more affordable rate on a comparator. In the end, the price excluding breakfast is 176 €, not exactly cheap.
In the end, it was a mixed experience. Even if the room was very nice, the service was almost non-existent, and the breakfast quite disappointing.