I have one ... got it years ago.
To shorten the story I was looking at good chairs after hearing Harriet Hargrave talk about ergonomics and quilters. [Un]fortunately the chair she preferred didn't fit my body. I saw the secretaries and worker bees at the office furniture store all had swoopers. I was allowed to take one home over the weekend. Loved it and bought myself one.
I have better posture, my back doesn't hurt, the neuropathy is more manageable using it, and it is adjustable. I heartily recommend them.
ali