Really nice hotel
I stayed here one night for business. 
I was pleasantly surprised by this hotel as I had only been expecting a generic Sheraton. instead, the hotel was really luxurious and the staff was very friendly. 
CHECK IN
The front desk staff moved quite quickly even though there was a pretty long line. I arrived early (around 11am) but they granted me early check-in, which was very much appreciated. The entire process was very quick -- no more than about 5 minutes. 
ROOM
I had a room on the 23rd floor with two queen beds in it. The room was very spacious, including a really pretty window seat looking out onto the city. The desk and chair were well-appointed and the internet worked well. The bed was extremely comfortable and the linens felt fresh. The bathroom was average, though very clean and well-equipped. 
CONCLUSION
I didn't use the gym or order room service, so can't comment on those. That said, I'd highly recommend this hotel if you're staying in Seattle. The location was great, the room was nice and the staff was friendly.