The Aeron has two major flaws, IMHO. It looks like the Cosm may have the same.
1.) Arms that recline with the back which causes your wrists to have to break to reach the keyboard
2.) The "trampoline" design of the seat means the front edge of the chair digs into the underside of your thighs.
This was the dealbreaker for me. I tried one, but just never found it comfortable no matter what adjustments I made. Instead, I switched to the Humanscale Freedom. While it lacks extensive adjustments that many find essential, it's been a great chair that has held up very well. In the few instances where parts have worn due to age and use, the company has stood behind the product and shipped me replacement parts with no questions asked.
People can say how much they love their Aeron all over the internet, but you have to understand what that means. They are just saying that they feel good while sitting in them, which often means they sit hunched over and it makes them relaxed. This doesn't mean the chair is helping them in any way. Often it means that the chair is compensating for their poor posture and making them feel good despite not being healthy.
You can see videos all over youtube of people actually working while sitting in Herman Miller chairs, and they all have poor posture. For example:
https://youtu.be/_R8bIIQxajA?t=15
https://youtu.be/cGEb-q5JMU0?t=17
Most chairs above around $500 will be fine. That is to say, you will still suffer serious health issues like everyone else who sits down all day, but the chair should not cause any pain while you are sitting down.
If you have back pain and so on, you should probably go to the gym, which will be the ultimately way to feel comfortable at work and everywhere else. Although, it still will do little to reverse the effects of sitting down all day. Programming is a career that guarantees immediate and serious health issues due to sitting and poor posture.
Herman Miller Aeron for example is great for people who are either small or sit "correctly." If you fold your legs under yourself, it is super uncomfortable.
My finalists were the Aeron, Embody, Steelcase Leap, and Gesture. The Leap and Gesture worked much better for my lazy ("natural") seating position. I ultimately purchased a Leap because the Gesture's arms shifted every time I stood up, and weren't as supportive.
Also our local dealer matched a major online dealer ($150 off).
I use to buy and sell used office furniture in the early 00's to pay for college.
But does nothing for leg length, which is the issue. As I said in the post you replied to, if you fold your legs under yourself the Aeron doesn't work.
For smaller people, they likely won't notice it, but for larger/taller the back of your legs brush against the underside/front of the chair in that position.
The Aeron seems to want you to sit correctly or not at all.
I tried the B and C, both were uncomfortable for my normal seated position, my legs literally hit the underside/frame. For a smaller person, with shorter legs, they will likely have a better experience.
I haven't had the luxury of testing other high-end ergonomic chairs, but I had to buy an Aeron for my home office as soon as I started getting serious about remote-working.
I can sit in this thing for a lengthy 12-hour shift and feel physically OK doing so (with some regular small walking breaks of course) - and I cannot say the same thing for any other chair.
I also think it just looks fantastic, it's definitely iconic and I have expressed my interest to Herman Miller in this new chair even though the one I'm sitting in right now is five years old and still feels mint condition.
Judging from the photo, this chair looks like it has the same problem.
I can't for the life of me figure out how or why anyone considers these chairs to be comfortable. Maybe my back just has a weird shape or something, but these chairs seem to literally fight to keep you from sitting up straight with a healthy posture. And yet, everyone seems to love them. It feels like some sort of bizarre conspiracy.
To be clear, this is not just my initial impressions. Everyone loves these name-brand luxury chairs so much that I've owned three of them over the last ten years (a Mirra, an Embody, and a Humanscale Freedom), because I keep thinking maybe I just need a different model, or maybe I haven't figured out how to adjust the damn things properly. They all feel well-built and high quality, but they all feel more and more uncomfortable the longer I sit in them, and I can't find a way to use them that doesn't seem to cause progressively worse back and neck problems. I can't figure out where the disconnect is happening.
Instead I got a Cramer Triton which is a fairly basic looking chair, but I found comfortable for working at the computer and it was rated for 3 shift use with a fairly long warranty. Later I got a total of maybe 6 of them for my company and they held up really well.
I left that company and the new company had a bunch of Aeron chairs, the best I could find of the unused chairs was one that I could get into a reasonable position but couldn't adjust at all once it was there.
Fast forward 4 years and yesterday I spent about 30 minutes sitting, mostly using a standing desk. :-)
The quality is definitely far beyond the office max special. I was surprised by the box the thing came in - absolutely massive. The chair is a tank
I've got 2 Aerons in my home office right now and they're awesome. Cost me £100 each, 6 months old, bought from a government department who paid a fortune for them. That's where your tax money goes it seems.
You don't need fancy chair if your back is not supporting a huge gut or is strength atrophied from never using it , you don't need a fancy mattress if your body is tired and your mind calm.
I found a ~$150 chair on Amazon that is so much more comfortable and affordable.
