I've spent some time testing the various HM chairs. I actually don't think the Aeron is the one for me. The lumbar support feels like a knife in the back. Next weekend when I make the purchase, I'll either get the simpler, firm-backed Mirra; the high-back, rest-your-head Liberty; or even the super simple Chadwick. If only a store had an Aeron with Posture Fit that I could try.