The Evans events – £20 – broom wagon, 2x cake stops, timing, no worries about following the route.
The Wiggle events – £35 – as above, but you get a tshirt and a crappy medal in addition.
Both allow you to not really think about routing for the day and will give you a route you might not have tried before.
I’ve done both, the Wiggle events generally have a bit more going on at the end (i.e. shops in tents) but aren’t that much different.
I’m doing a few Evans rides this year, as motivation for actually getting out and doing something different rather than the 20 minute drive to Swinley. (Also, they do 3 for 2 in January).
I would say if you’ve already got the route planned, don’t pay the money.