I've always liked Mailman a lot, and prefer mailing lists to web forums, but we've just recently made the decision to not enable it by default in Virtualmin (for the past 12+ years, we've enabled it on every install and made it easy for non-privileged users to create new lists and such). But, when we recently assessed how many of our customers were actually using it vs the resources it requires, we can't justify it.

This new version doesn't alter the reality that very few website owners want mailing lists, anymore. But, it makes me want to start some new mailing lists (I don't currently maintain any Mailman mailing lists, though in the past I was wrangling dozens of them).

The UI looks great, and the new architectural changes sound great, too. It's long overdue, though.