@Scrbblchick -- I've been and it's everything you think it will be. It does not disappoint. You can see all over the city, and even the University of Washington campus and their stadium. You can also see right over Puget Sound. It's an incredible sight.
The only part I didn't like was the elevator ride up and back down. It was about five minutes and I got a touch of claustrophobia. I just closed my eyes and remembered that thousands of people visit every day, and the elevator gets them up and down every time.
Seattle is a beautiful city. I'm so glad I was able to go. I have wonderful memories of the place. There is so much to see and do.