It is very comfortable. The ergonomics on this chair is perfect. The employee I bought it for has sciatica nerve pain in his lower back. He has tossed out the pillow he sits on since having received the chair. The support is great he feels supported in the right areas of his body while sitting.
My wife has had the red one for a couple of years and loves it. I did not want a red or black one . When I saw the charcoal gray one and it was on sale I ordered it immediately. Could no be more pleased.
The seat is contoured too narrow for my butt and is pinching me plus it rolls my hip out. the lumbar support is too high for me at 5'11". The chair now sits 3" lower than when I bought it a few weeks ago causing me to have to sit with my legs crossed. I am planning to take it back as soon as I can find a way to get it down the stairs. I was so disappointed. for the last 10 years I have bought my chairs from the state surplus warehouse and gotten better chair I thought I would buy a new chair this time and see if they lasted longer. It didn't last nearly as long.
The chair gave me extremely bad lower back pain after a few days. It was the only thing that had changed in my life so the chair had to be it. Returned it.
I have tried several office chairs and the Hyken is the best for my lower back that I have used. My son uses his for gaming for hours without any back issues. That is what sold me to get the chair. No regrets.