This is by far the most comfortable office chair I have ever had. It's a great value for the money and more comfortable than chairs 5 times the cost of this one!
I have used the chair for about a week and find it comfortable for long periods. I like the adjustability options including the height of the arms so the chair can go under a desk. The lumbar support is pronounced which is almost too much of a good thing. The support can be adjusted up or down but that is all. I wish it were possible to make it less supportive.