If I could do it over again, I probably would have gone with living in the trailer park. Rent is much, much cheaper there--especially if you split it with roommates. During my time at ISU, I lived in an apartment and, I'll be honest, after rent and utilities every month, I had a really difficult time making it on the small amount the school gives you for living expenses. Even having an extra $1000-2000/year would have helped me out considerably; I probably could have saved that much, if not more, on rent had I gone for a trailer instead. Also, as previously mentioned, being able to easily walk to and from the vet school is always nice (you're still removed from the actual main ISU campus, distance-wise). The majority of people living in the trailer parks, particularly Old Orchard, are vet students so you'd be in good company.
I visited a few friends' trailers while still in vet school and, yeah, they can be surprisingly roomy. Three people shared one with two pets and it didn't seem too terribly cramped, at least to me. *shrugs*
The only semi-substantial con I can think of at the moment is that you'd be kind of on your own for repairs and whatnot, if that is a dealbreaker for you.