Arm rest height adjustment is very generous. This is one of the few office chairs that can have the arm rest adjustment that fits my need. I have a long torso-to-upper-arm ratio so I need the arm rest to be high. This chair delivers. The head rest is also at a very good height and just the right curvature for me. Very comfortable.
Assembly was a breeze for my 13 year old son. It's adjustable just enough to be comfortable without being complicated. The head rest is the only part that isnt really adjustable to use comfortably. It can simply be removed though. It's comfirtable. After sitting in it several days in a row at work I had none of the pain or stiffness I was getting from other chair options. We'll see how it holds up over time but seems well made. My only other challenge is wrestling my 13 year old for who gets to use it.