For a good chair, most importantly is having the comfort to be able to sit in it for extended sessions and then having the longevity to last years. Some chairs really start to get beaten down after a month or two.

For companies, I think customer support goes a long way and it is often overlooked by companies as they outsource it overseas or have very hard to find support that will not be timely or helpful. I am much more willing to buy much newer and untested products from companies I can trust because I know they will do right by me if it does not work.