I love the back support and the other features of this chair. The left side is a 1/2 inch higher than the right. I've taken it apart and put it back together but it is definitely not a solid flat seat. Didn't notice it till about mid day when I felt myself leaning to the right so bad.
Got it delivered on time easy assembly and over all very good for the price. There is no lock in the wheel so if we use it in hard floor it is bit uncomfortable.