I had a similar experience with the Aeron. I got one used a few months ago (it was still like $500 for a used Aeron in good condition), and for the first couple weeks I hated it. Now that I'm used to it, I barely notice it's there. It's much more comfy than any other office chairs I've used. I still wish conformed to my slightly-weird lower back a little better, but it isn't a big deal.