Well, I got around the Viking Challenge in one piece! One puncture (loads of people suffered on one section due to the area being cleared of trees and shrubs leaving lots of small sharp bits of wood about the place.
However, it wasn't at no expense. If you managed 10mph on most sections (bar the road links to each section) you were flying. The mud was unlike anything I've ever seen, so much so that by about half way around I'd completely burned away my brake pads, front and rear. It was that thick that even trying to turn the wheel around was impossible because it jammed on the fork... Crazy stuff.
Luckily there were quite a few water splashes about, so you could hit those and clear off the majority of the muck, but the bike is absolutely bladdered and will need a total strip down. Hopefully the (new!) brake pads will be the only casualty!
I took one pic - having got back to the van and clearing up myself a bit, I took one of the bike:
Most of the real thick muck had come off, but you get the idea!