I’ve been using my Aeron chair for about 2 and a half months now, and I’m quite happy with my decision to go with it.
The chair is comfortable all the time, but when I settle in with the footrest and get into proper position for work at my desk, it is really comfortable. The mesh seat and back especially proved their worth during the hot spell we had a few weeks back when the A/C couldn’t keep up every day.
I used an Aeron for several years at the BigCo back in the Bay Area, but never thought much of it. Having been without one for a couple years, I really appreciate it now.