Please don't blame students for you slow internet, it's not our fault; it's VM (and it's predecessor's) fault for overselling. I live in a virtually exclusive student area and the speed is excellent. Students /= slow internet.
The easiest way to find out your UBR utilisation is to post a friendly request on the virginmedia.support.broadband.cable newsgroup:
http://www.virginmedia.com/help/cable/newsgroups/