I was wondering about this. I've been trialing a standing desk - the best part is if you are thinking about a problem you tend to walk, where as if you're sitting down you just tilt your head to the side. But after 4 hours or so I find I get a sore back. I've been "mixin it up"... standing for an hour, sitting for a couple of hours. Or sitting in the morning, standing after lunch... so far it feels pretty good, but I…
I don't have the option of swapping it around; my "standing desk" is a regular desk with cardboard boxes and telephone books stacked on top ( http://instagr.am/p/MUmlP/ ). At this point I can't get a new regular chair, let alone a high stool, unfortunately.
I'm giving it a week; after then I'll decide whether to switch back or not.