Here is my stay report from my recent one-night stay at the GH Seattle - an overall great experience.
I was able to check in to my upgraded Corner King room around 9 AM (no suites available online, and none were offered when I asked at check-in). I was on the 20th of 30 floors with a view facing the Sheraton Grand and a small view of the Sound in the corner window. These Corner King rooms really are more like junior suites in my opinion as they have a living room separated from the bedroom by the bathroom-adjacent hallway. There are even 2 separate AC thermostats due to the room's size. Overall, I was really impressed by the luxurious feel of the room with the doorbell, electronic privacy button, electronic window shades, and marble bathroom with separate soaking tub and glass shower. The decor might qualify as a bit dated, but something about the woodsy look really did it for me. It honestly felt like I was in a nice spa. The bed was very comfortable, and the water pressure was great. They had also upgraded the TVs in the rooms as they were much bigger than the ones shown on the online photos.
Breakfast is still served through In-Room Dining with a $25 limit for Globalists. I actually quite enjoyed my waffles and side of bacon, and it was delivered incredibly promptly (like less than 10 minutes). The Grand Club on the 27th floor is open for waters, coffee, and granola bars. I was very impressed with the hot chocolate (much more than the HR's hot chocolate across the street).
Service was similarly great as everyone I spoke with was very pleasant and efficient.
For my first Grand Hyatt, I was really impressed with the luxurious feel of the experience. From the design (I especially loved the look of the elevator lobbies on the guest floors) to the in-room amenities, the Grand Hyatt Seattle really exceeded my expectations.