Hi, I'm also looking at universities for Illustration, when I was researching for choices most of what I saw was more Falmouth positive than Brighton! But it definitely depends on what you are looking for in a university, I do think it's primarily what you make of it as they are very different locations (Both are artistic places but Falmouth is a small-ish coastal town and Brighton definitely is NOT small) I'd say think more about what you want from the course and think more about what experience you are looking for.
Hope this helps a little!