The headrest is only useful if you are the exact torso length for the chair. It actually works fine for my colleague who is my height but for me it lands in a place that is completely uncomfortable and not ergonomic so I just removed it. It can be “adjusted” but it just tilts up and down doing nothing for where it hits on your head.
This chair strikes a perfect balance between comfort and support! I see more and more of them popping up in my workplace and everyone has good things to say about them.