What should I check before buying a new Aeron office chair online?

[lesert]

I have been thinking about upgrading my desk chair and would like some advice from people who have actually used an Aeron for extended periods. My current chair is becoming uncomfortable after several hours, so I am looking for something with better support and adjustability.

The Herman Miller new Aeron chair seems to receive consistently strong feedback, but I am unsure which configuration makes the most sense. Is the lumbar support upgrade worth getting? How important are the adjustable arms and tilt controls if someone works at a computer for most of the day?

I also found Madison Seating during my search and noticed they carry Herman Miller products. Has anyone here ordered a Herman Miller new Aeron chair from them? I would particularly like to know about the buying experience, chair condition, packaging, and how accurately the product description matches what arrives.

One thing I am trying to understand is whether there is a major difference between purchasing a brand new model and a refurbished chair. If the refurbished option is professionally restored, does it still provide the same comfort and reliability, or would buying a Herman Miller new Aeron chair be the safer long term choice?

For those familiar with Madison Seating, how was their customer service if you had an issue after receiving your chair? I would also like to know whether anyone experienced problems with returns or warranty coverage.

What factors would you personally prioritize before spending this much on an office chair?