Been quite a few times both working and as a punter.
It's worth experiencing that's for sure. I think I would only go back if I got free tickets but I have my 'festival' reasons for that and there are thousands and thousands of people who enjoy it every year.
Be prepared for it to be wet and pray that it isn't, be prepared for a long walk from CV field, no chairs allowed in arena, none of your own alcohol allowed in Arena.
But most of all as with any festival, it is what you make it, so wear your smile at all times and you will have the best weekend of your life