Susie & I have just got back home from Sidmouth after a long weekend of doing admin stuff in preparation. Our tent is already up, on the Festival site, and as of 5pm yesterday (Monday) I can report....
There is no mud. There are no ruts, and the ground is firm enough to make my arms ache from hammering in tent pegs.
All the really heavy stuff (generators, loos, showers etc) seems to be already on site. All marquees, electricity cabling and water pipes appear to be in place, including the overhead lighting. On Saturday, I noticed more hardcore being laid in areas which have been a problem in the past.

FYI the word is, they are going to be very strict on early arrivals this year(no admission before midday Wednesday without explicit permission)

John