The lumbar support is heavily uncountable. Puts a lot of pressure on your lower back which forces you to lean forward and that's the opposite of what a chair should do.
It's almost a great fit with the exception that the arm rests are too high at their lowest setting. Considering this chair is meant for larger people it seems like an oversight in the design that it cannot accommodate people with long arms. I've been using it without the arm rests and it's been good otherwise.