Super
First of all, it is important to understand that the choice of a chair depends very much on the weight and build of the person (yours, not the chair's)
Very strong (when you are over 100Kg it counts).
Perfect seat width (Pay attention to the width of the seat!)
The seat is just the right amount of stiffness. Stiff but comfortable when you play for hours on end.
The head and lumbar support is very good (I was a bit worried about this)
The seat height is also perfect (for a person of 1m80)
A bit expensive, but if you don't want to change your chair every year, it's worth it.
I've had it for two months now and I'm really happy with it.
A piece of advice: Before buying it, measure all the dimensions at home to see if it's right for you BEFOREhand.