I'm quite lucky in that I don't live far from the Clogg factory, so it's not a problem for me to go in and get measured up for mine. Consequently, my clogs are really comfortable. In fact, I'd go as far to say they're the most comfy shoes/boots I have. But I do have a couple of friends who bought second hand pairs and they did struggle with them somewhat. Funnily enough I was over in Holland watching the Stranglers last week, and while I was there I met some Dutch friends of Dutch friends and they had Dutch clogs. They said the same thing about a measured up pair being very comfy, but 'off the shelf' being not so comfy.
Anyway, I've rambled on enough now. Back to work!
All the best,
Johnny