aspiringlinguist2014

Ann Arbor is much, much smaller than Seattle so the differences here are pretty big despite the fact that both are well-educated cities that are wonderful places to live. Because of its smallness A2 is very easy to get around on foot or on bike and while public transit exists in the form of city and UMich buses I wouldn't necessarily say that they're a big part of life in A2 unless you're regularly going from central campus to north campus or something like that. A2 is pretty close to Detroit and the metro Detroit area, which is massive, but I think you'll find that the vast majority of people who live in A2 have very, very little involvement with the City of Detroit (which, for all of its knocks, is a really neat area to explore).
 
Is A2 dominated by undergrads? I don't think so. A2 is very well-segregated between undergrad districts and grad/adult districts--speaking in terms of nightlife, there's one street that will be 90% undergrads on any given night and another a ways away that would be 90% grad students and adults. There are definitely plenty of more mature student neighborhoods too so it's possible to find a place to live that isn't going to be a raging party ever night. That being said, football still owns the town so on fall Saturdays the entire city is going to be a zoo--if you embrace it you'll love it, if not you'll probably want to claw your eyes out.
 
Do people get bored in Ann Arbor? I don't think so. I haven't lived there for a long time outside of undergrad but in my experience graduate students and adults love living there because like Seattle, it's a very energetic and educated community. If you're used to a big city environment like Seattle, Chicago, or New York, A2 may seem kind of small to you but overall I think it's an awesome place to live.
 
To speak to housing for a second, it depends on what sort of housing you're looking for. In campus neighborhoods most students pay in the $600 range but if you want to go nicer, or in a single, then you're probably looking at $800+. The caveat is that if you're willing to live farther from campus (perhaps outside of walking distance) you'll get much higher housing quality for cheaper, but I wouldn't recommend that because Ann Arbor is great when you can walk everywhere.