Mostly forgettable. They put on so many events for people to get wasted at on all the different campuses. People move in at any time up til the beginning of Fresher's Week, it's a fairly even spread, but Saturday is very popular as parents have time off work.
It isn't Fresher's Week that you should be looking forward to, it's the whole thing. Not many people stay hanging out with the people they were with on Fresher's Week.
The Fresher's Ball is pretty crap tbh. I'm not trying to put a downer on it, Manchester is awesome to be at, but people often look forward to Fresher's Week faaaaaaaar too much.