I only got to visit one school before I sent in applications. Although I liked where the school was located, there were a lot of other things I didn't like, and I ended up deciding not to apply - so it was really beneficial for me. It was actually under similar circumstances - I just happened to be nearby for a completely different reason so I thought I should take advantage of the opportunity.
Then, before I made my decision between my top two choices, I visited both of those. One was only forty-five minutes away though... the other seven hours away, but the latter was worth it too.