I have the aeron, it's nice but a bit uncomfortable if you sit in it in any sort of non standard way, I sit with my legs crossed and my cat in my lap and unless I pad the heck out of the bottom with extra pillow or blanket the hard plastic digs into my feet and legs.
For me a far more comfortable approach is a monitor on a stand and a comfortable easy chair, along with a split ergonomic bluetooth keyboard. Embrace our wall-e future
These things are sitting machines. If you're going to spend money on one of them, read the manual, set it up properly for your body (seat height, depth and tilt, backrest tension if it's not autoregulated, lumbar support, armrest width, height, angle, and/or depth...), and learn to use it as intended.
If you do, it's money well spent (orthopedists and chiropractors are way more expensive); if you don't, it's a waste of money and intervertebral discs.