I think it depends what you were sitting on before. If you go from wooden chair to aeron, you feel the difference.

Ditto. (Well, at work, not right now). I was lucky enough to snag one from a different room in my office. I was excited because of the magical stories I've heard about Aerons. There's lots of little knobs and levers to fiddle with, but even after extensive personalization, it's not all THAT comfortable.

It might not fit you.

It's not really made for women's hips for example, so I've never sat in an Aeron I liked. It digs in.

Most very good chairs come in different widths/depths for people of different heights/weights.