I sit in an Aeron chair (like the above) everyday at Warner Bros. It's funny. They seem to have them everywhere except in the bathroom stalls. I'm used to them, and I think I love them.
Unfortunately, my home studio furniture budget ran out when it came to the chair, and since I'm sitting in this "Office Depot Special" at least as much as my WB chair, my body thinks it's being punished half of the time.
One day my home studio chair will be put out to pasture, and I will graduate to the Aeron dream chair 24/7. (Problem is, I haven't figured out how to sneak one home yet.)
My chair at home: