A very dangerous thing to be wearing anywhere other than a restaurant.
I'm in the medical field, and I wear them (Dansko professionals, with the full ankle) all day, every day. I love them. As far as sizing, I went up a half size from my normal shoe size.
You do have to adjust to them, because they feel different from other shoes, but they truly do feel better. My feet don't hurt at the end of the day, and the shoes really look nice, and are much more flattering than those crocs.
I've been in them at the barn, and as careful as I was, I managed to get them muddy.. fortunately, they clean up really well. I also put some leather conditioner on them and they are gorgeous!