I have an Embody, and while I found it comfortable initially, after having it a couple of years now, I'm wishing I hadn't spent so much on the chair. (prices here are about twice US!)
I wish I had bought an armless chair, as they don't allow me to get as close to my desk as I would like. A good keyboard tray might be the solution to that, but I have always found them to get in the way of my legs, as I'm reasonably short and need my chair up quite high for proper posture, which doesn't leave much room between the desk and my legs. The arms are ratcheted in such a way that they are either too high, or too low for proper support. I don't find that they are long enough at the back either, nor do they change position/height when you recline, so I am constantly adjusting them. Really, it feels like the chair should be used armless with a reclining desk such as this:
http://www.youtube.com/watch?v=Nq9eo5ml5pIThe chair itself seems designed to be reclined. Even at the most upright setting, with the highest back tension, it does not offer any support if you are sitting up straight. I'd say it has you leaning back maybe 10–15°
Because it seems designed to be reclined, I find myself wishing that there was a headrest attached to the chair.
The seat angle is not adjustable - it always angles down maybe 5° rather than being flat when sitting upright, it only changes angle when reclined.
The seat depth adjustment is flimsy. When extended, it's just resting on two small plastic runners, so it flexes a lot and plastic rubbing on plastic squeaks/creaks.
The back is too narrow. This is by design so that you have more range with your arms if you are reaching off to the side to pick up something off your desk. (it seems like they should be encouraging rotating your chair instead) I find that it digs into my shoulder blades if I don't loosen the back adjustment, which means it's no longer conforming to the curvature of my spine properly. You only have one control for the back which changes both the curvature of the lumbar support and brings the curvature of the chair back in at the same time. Looking top-down on the chair, it changes it from a flat back support to a more u-shaped one as you tighten it up. So to have flatter back curvature that stops it digging into my shoulder blades, I lose proper lumbar support.
It's a noisy chair. Whenever you recline, it creaks as the shape of the back changes, and every time you adjust the reclining angle, there is often a loud click from the chair the first time you recline at the new setting as it locks into place.
It's not comfortable to be in all day. While the conforming back/seat design is very comfortable initially, I do wish there was some kind of padding rather than just a thin fabric coating. Also; buy it in black. It will discolor fairly quickly and while you can unhook the bottom of the seat, the cover is not removable for washing. I contacted Herman Miller about having mine recovered with black fabric, and was told it would cost half of what I paid for the chair in the first place. (about the full retail price in the US) I have just decided to live with it, and would rather purchase another chair than spend that kind of money on it.