On a less emotional level: the way they were cast is night-and-day different from what's sold as cast iron today. The pores on my Griswold are an order of magnitude smaller than those on my Lodge (that I just haven't gotten around to throwing away because I never use). It's a much smoother surface, and therefore develops a very different - and much better - patina than the modern stuff can/does.
Edit: 120, not 220 years old.