Personally, I hate the W concept. However, I would seriously consider staying at the W Doha on my next trip. I cannot speak for the rooms, but the common areas and exterior were striking and had a modern but not dysfunctional feel to them. The staff were friendly and didn't seem to have the Witude. Market and Spice Market were both excellent. The food was well prepared, though not quite to the standards of the JG in NY, and the staff was friendly and accommodating, even for a single diner on busy nights. The hotel is in a good location, not far from the diploarea and walking distance from the city's largest mall.
The Sheraton is nice but showing it's age. The staff was generally friendly but fell down in many areas. They gave me a deluxe room on a high floor as an upgrade because the hotel was hosting a number of dignitaries that took the suites. Food was decent, though the smoke got to me after a while. The lounge was a nice place to relax. Overall, it was a decent stay.