Just completed a stay at Westin Bellevue this weekend. Not much more to add then what has already been posted.
I only have SPG Gold Status, and was "upgraded" to the 14th floor, which is the Preferred Guest Floor. I was told there's nothing different on that floor, than any other floor, other than the fact that you get a free bottle of water.
My room was near the elevators and fairly noisy (could hear neighboring rooms doors closing etc.) I had inquired about a more substantial upgrade at check-in, even offering to pay for one, but was told the hotel was sold out, and no upgrades available.
You can self-park in the underground Parking in Licoln Square on Levels 4 or 5, and it takes maybe three minutes to walk from the parking, take the elevators, and enter the Westin.
In room High Speed Internet Access is available for $11.95 per 24 hour period. However, another option is Bellevue Square across the street offers free wireless internet access.
Some great dining options in the immediate vicinity including a McCormick and Schmicks, Cheesecake Factory, Joeys.
Another restaurant I quite enjoyed for a more casual dinner: Z'Tejas Southwestern Grill.
I was in Seattle to watch the Mariners/Red Sox series, and it took me about 30 minute to drive from the hotel to Safeco.
Overall, a decent hotel, but nothing special. I may try the Hyatt, or the Bellevue Sheraton for my next trip.