Yeah, had a bash in December 2003.
It was in the area of Thun, going south along the lake to Interlaken and back round again the other side.
It was cold, but dont carry anything other than water, stickies, woolly hat and gloves and waterproofs.
It didnt feel like a competition, more of a parade of old fashioned uniforms walking the local towns for a few hours. We tabbed off all professional and we stood out like sore thumbs!
We did about 40 miles I think and 'won' by miles. The checkpoints were conveniently located in pubs and had sweets to grab and obviously plenty of liquid to hand.
We stayed in the Swiss army camp in Berner itself. Big barrack blocks, normal transit type facilities.
Good laugh all in all, would be happy to do it again any time.