I have an Aeron Chair (it's partially visible in the first pic in my first post about my home office setup).
A few things about the Aeron:
1. It comes in three different sizes, so you need to make sure you get the right size. Even if you order online, it's advisable to check it out and actually sit in one in a showroom to see how you like it. (I have a feeling you're a fellow who does his research before buying, so you're probably already aware of most of the things I'm writing here.)
2. It has quite a few controls, but one control it does not have is one for adjusting the seat depth, i.e., for moving the seat pan forward or backward. The back of your knees is supposed to clear the front lip of the seat pan by about 2-3 inches. I have rather short thighs, so I clear the front of the seat by just a hair under 2 inches (on a size B Aeron). The three different size options go some way to make up for the lack of a seat depth adjustment, although perhaps not completely.
3. You do have to make the proper adjustments for it to be of any ergonomic benefit. But that also means that it can't be a chair you share with someone else, or else you'd have to readjust the height, tilt, tension, back suport controls, etc., every time you sit in it.
4. If you're going to spend that much on a chair, I would advise spending the few extra bucks and getting the fully adjustable version with the PostureFit thingie. The standard Lumbar Pillow is something of a joke, as far as real lumbar support goes.
5. I don't seem to have major back problems (knock on wood), but for the first couple of weeks after getting the Aeron, I developed lower back pain. That was mighty dismaying, after spending all that money on an ergonomic chair. It might have been because of improper adjustments. But the pain disappeared and hasn't come back.
6. I experienced a bit of buyer's remorse after getting the Aeron, because I kept on reading about office chairs on the web and found out more about the Steelcase Leap Chair. Had I waited a couple of more weeks I would have gotten the Leap instead of the Aeron. Unlike the multiple size options of the Aeron, the Leap is one-size-fits-all, and has more controls than the Aeron, including the seat depth control that the Aeron lacks. There's even a mesh version, I think (although I would have probably gone for the leather version). I encountered several instances on the web of people who switched from the Aeron to the Leap and claimed the Leap to be the superior chair, but never the other way around.
7. I have read some complaints about the armrest height adjustment mechanism slipping and not holding to the adjusted height. That hasn't been a problem for me.
8. I have also read some compaints about plastic parts breaking off. Frankly the build quality seems really good to me, definitely superior to what you would find at Staples or Office Depot or Ikea. And there's also the 12-year Herman Miller warranty to protect you if you buy new from an authorized dealer. (And for that reason, I would avoid places like luxurychair.com or getting it used on eBay, although I just tried to go to luxurychair.com and the web site isn't loading so maybe they went out of business after all the complaints).
8. Aside from the Herman Miller Aeron and the Steelcase Leap, other chairs you might want to look into are the Humanscale Freedom and Liberty Chairs. Both the Freedom and Liberty take a different approach to ergonomic seating; they minimize the available user controls, on the grounds that most users don't bother to use them, and they automatically adjust to the way you sit, supposedly. I have never sat in a Freedom Chair but I have tried out the Liberty, and it's pretty damn comfortable. And there are a couple of lower-priced Herman Miller options, the Mirra and the Celle.
Also, I am quite taken by the Swopper, which is essentially a giant cushioned spring you sit on. If I were to get a second chair (which I'm not because I don't have room for it), I think I would get a Swopper to supplement the Aeron. Also, I know of someone who, though quite satisfied with his Aeron, replaced it with a Hag Capisco, after reading Galen Cranz's book, _The Chair: Rethinking Culture Body and Design _, which I gather puts forth the proposition that perching, rather than sitting, is more natural and healthier.
9. The Aeron Chair carries a lot of cultural baggage. I mean, do you *really* want to set your ass on an icon -- perhaps *the* icon -- of late 90's dotcom excess? I personally don't mind. I sorta like the idea of owning such a significant cultural artifact. Not only is it a potent cultural symbol, but it is a significant aesthetic object (it's in the design collection of MOMA). It's revolutionized the way we look at office chairs. I think it's beautiful as an exoskeletal sculptural object, but I know mileage definitely varies on this.
If I were to buy today, I'd have a hard time deciding between the Aeron and the Leap. But that being said, I love my Aeron. It is the most comfortable chair I have ever owned (I haven't tried the Leap).
Cory Doctorow loves the Leap Chair and the Think Chair:
http://www.boingboing.net/2006/10/05/steelcase-think-self.htmlAnd if you haven't done so, check out Bruce Sterling's Wired article on the Aeron, the Leap, and the Freedom:
http://www.wired.com/wired/archive/8.07/chairs.html
