Does Seattle have a subway or other rail system? I've been there once, in 1994, and I remember a pretty gnarly rush hour getting into the city on a weekday afternoon. The freeway was locked-down for quite a distance. It was grey and drizzly the whole time, which gets old in a hurry. You could tell that the place would be breathtaking if the sun came out, however; very green and hilly, beautiful neighborhoods, etc...
One complaint I had, which I have in all smaller cities, is the lack of awesome+cheap food everywhere that you take for granted in a big city. I don't want to get into a pissing contest w/ the (considerably large) PNW contingent here, but it's not the same as L.A./NYC/Chicago in this regard and it's something that we in the big cities take for granted on a daily basis. Coming from Rochester, MN., this will not be a factor. You will think that you are in the most cosmopolitan, advanced city on earth in comparison. What are you doing there? My sister did her residency at Mayo back in the mid-'90s, she commuted every day, (90 miles one way), rather than get an apartment there. She had 2 little ones at home in Mpls.
My one and only trip to Seattle was for a weekend, and the afternoon I got there was the day that Kurt Cobain killed himself, so the whole weekend had a bit of a down vibe over that. The hipster parts of town really do have a dreary, junkie feel to them. It's undeniable. Seattle is where the term "skid row" originated, and you can see why. Like most cities, it is really two cities. You can never completely isolate yourself from the "other city", though. My other complaint, and it might not be a factor for everyone, was the overwhelming whiteness of the place. I thought that I was from Caucasia, (Minnesota), but you haven't seen pasty skin until you go to Seattle. I'd love to have the Patagonia franchise up there, holy christ. Nothing wrong with being white, (I'm practically an Albino), but there is definitely a point where you just say, "this is unnatural".
All in all, depends on your past experiences, tolerance for drizzle, and need for big-city diversity. (With all of the good and bad that it entails). The people are fantastic, and you can forget about skin cancer up there. You will look like a new-born baby at 60 if you move there young enough. Super-easy place to cop if you become a junky. That pretty much covers it.