I've had three months to try to get used to this chair, and I have to say I'm disappointed.
I am a 5'7" woman.
My biggest issue is with the lumbar support in the back. Try as I might, I could not adjust the height of it to my liking - even after snapping something in the track and injuring my thumb in the process, to be able to move it up/down in the first place. It does not adjust forward/back independently of the seat back - so you're either leaning back too far or it's digging in. There is no knob or lever to move it up/down; my thumb is still healing and the piece is still stabbing me painfully in the small of the back. The thing aims perfectly at the few inches somewhere between my tailbone and the waistband of my pants. I have also not been able to find a way to remove it without damaging the chair further.
The arm rests are super adjustable. They adjust easily up/down, out/in, and forward/backward. You can get them into exactly the position you want. Except that they don't stay there. The up/down has a locking lever, but beyond that the arm rests themselves are constantly slipping and sliding with my horizontal arm movements.
Then there's the height of it. I've just moved my office into another room where the desk height is about 2" higher than the old one because I've incorporated a portable elliptical exerciser under the desk and need the knee room. And to my surprise, the chair height will not rise any higher than 20". Not sure what the height of a typical chair is, but my feet are easily comfortably on the floor at that height. I can't imagine how someone 6' talI could find this comfortable. I am now looking at either a booster for the seat, or a new chair.
I love the mesh back and fabric seat - much cooler than the old leather chair I replaced. The wheels glide effortlessly - a little too easily, actually, as leaning on the desk perpetually pushes me back away from it.
For anyone who wears their hair in a ponytail at all, the headrest does lean back and forth. I push mine all the way back and out of the way. But it does not raise or lower to allow for a lump on the back of your head. Nor does it come off.
Overall, and especially given the cost of this chair, I am sincerely regretting this purchase.