I'm 5'10" and 185 lbs and this chair was comfortable for about 3 months. Now as soon as I sit down I get burning/numbness in my legs and rear end. I sit for at least 8 hours and the only chair I've found relief with is the Aeron (well worth the money for a 12 year warranty).
This chair is comfortable and adjusts to fit well to whomever is sitting in it. We bought several for our offices. Some folks are not fans of the headrests - but those can be removed. I personally love being able to sit back now and then to rest my head. We will definitely consider purchasing more as our other chairs need replacing.