I agree with most of the posts.
I found the level of police in the area to be totally excessive. The police were obviously there to prove a point, but there wasn't even that number of police at half the protests I've been to at places like the nuclear base at Faslane. It can just as easily antagonise people as it does re-assure.
I also think that the town does pretty well economically for one weekend of partying which, from my experience as a non-St. Andrews student, really draws the students together as a community, and is no worse than a night out in Glasgow.