I'm signed up for the 200K. I'd intended to do the 200K last year but ran into bike problems (broken pawl spring) after the first climb up Blue Mounds and had to walk back up the hill from town. I still completed the 100K on a new wheel, but thinking back it was a blessing as I don't think I could have finished the 200K last year. This year I've got a lot more miles in, but it's still going to be tough doing all those hills in one day...
Maybe I just need to relax as I completed the DLD 200K last year...