Can't speak for Mutt, but, honestly, I really miss old text-based email interfaces such as Pine and Elm. Navigating through older emails was much, much easier, and there was not the visual cruft that comes along with so much email today. Email is for communicating; other than image/file attachments, there's really no good reason to have it be anything other than plain text. But that's not the world we live in.
I used notmuch/mu4e/emacs for a bit with my work email when I was in a role that got tons of email. The filtering, keyboard nav and plain text meant that the interface never got in my way and processing my email was lightning fast. Gmail gets close with filters/keyboard shortcuts, but emacs was much much faster and integrated well into my org-mode flow as well.
