I did it last year for the first time, entered in the 30km ride. It rained, and rained, and rained. It was kinda tough going in the sticky and slippery clay. I took a shortcut onto the 18km course as the going was so slow for me. It was cold. I was cold. I walked lots of the hills. In the end I had the most awesome fun on the ride, and thought the course was pretty good too.
I'm back this year, entered in the 30km again. (And probably just as under prepared as I was last year).