I live in the Seattle area, and my husband I stayed at the Westin in December. We picked the Westin because it's across the street from the Cinerama, and we were seeing the midnight showing of Lord of the Rings there (my husband is a big fan). Overall, we had a good stay. The one negative thing I could say is that getting an elevator in the morning was quite difficult. I don't know if there was some sort of conference going on and they were all checking out at once or something, but everytime the elevator doors would open, it would be filled to the brim with people from the floors above. The only stairwell we could find led only to an emergency-exit-alarm-will-sound door. So we ended up having to take an elevator up to one of the top floors, then take it back down, stopping at every floor to pick up more and more people until the elevator was entirely full, and then we just told the people waiting on every floor "Sorry, we're full." The whole thing took like 30 minutes, and was somewhat surreal. Other than that, it was a good stay, good service, the bathroom in our room wasn't renovated but wasn't bad either, nice bed, nice city view at Christmas time.

We're staying at the W this weekend, I'll post about how it goes with our Gold upgrade/late check-out requests. I've been in their lobby bar before and it's pretty nice.

In terms of location, the W is closest to the "financial district" (such as it is in Seattle), the Westin is closest to the shopping district and Belltown (cool neighborhood now being overrun by yuppies), and the Sheraton is closer to the convention center. But all 3 are within a 10 minute walk of each other.