I've had a Stokke Duo for 23 years. Varier is a new name for the company and the Duo is a milder version of Varier Gravity Balans [1]. It's been so good that I just recently had it reupholstered. I've tried Gravity and find it excellent as well. With a nudge you can change between four different positions. The positions are quite stable, it's not like a rocking chair.

[1] https://varierchairs.com/product/gravity/