I love my Herman Miller Aeron chair! I've had it for several years. It has been durable and comfortable. It comes with a 12 year guarantee. When I come in from working on the "estate" and my sciatica is screaming at me, sitting in it immediately relieves my pain. Mine has the optional adjustable lower back support. I added a third party headrest, so I don't get whiplash when I fall asleep. I bought it at a Healthy Back Store in Fairfax, VA.