If visiting didn't help, apart from being surprised, have a look at the course content see how it differs and which you would prefer, that might help. The differences between them as Economics departments is not really large enough to be note worthy, I would have thought that the location and the differences in content might cause one to suit you better.
Which does puzzle me, QM is London, Sheffield is a large city (4th largest in the England I believe?) and then Guildford is a decent sized town. They would be very different to live in and give very different experiences.