IMO, mutt is the best mail client there is when it comes to lots of high-volume mailing lists. I can catch up on all my lists so much quicker than with any other mail client.
Mutt is the only way I can keep up with my mail volume. The only time the UI doesn't react instantly is when it loads huge mailboxes. And it still does that faster than I've seen graphical clients load the same mailbox.
Add to that pretty much infinite customization, and it does indeed suck less.
If you have to deal with large amounts of mail for pretty much whatever reason, you can do it faster with mutt than with any other client I've ever used. Yes, there is a learning curve. It isn't a vim-style learning curve, but it is there. But if you're considering a command line MUA at all, you can handle it.
