Need advice guys. I've been using the Sihoo V1 for a year now, and while it's been decent (a bit wobble) - just want to experience sth new tbh lol. I decided to upgrade to something more comfortable and durable which is under $500,  I work long hours, often 8-10 hours a day, so I need something that will stay comfortable over extended periods. I have some questions:

• Which one is better between single-backed chair vs dual-back (sorry for not knowing how to call it)? It seems like the dual-back is more comfortable when I tried it at the showroom but it gave me a thought that the dual-back does not support my back as good as the single. The single-back give me the stiffness to my lower back which I think it will correct my posture better (?)
• What is the essential feature I need to notice when buying an ergonomic chair?

I’ve done some research and found a few models that seem promising:

Autonomous ErgoChair Pro

Steelcase Series 1

Nouhaus Ergo3D (dual-back)

Hinomi H1 Pro (dual-back)

Any other recommendations? Hope can find my perfect fit. (I'm 5'9" & 165lbs)