I've forgone traditional auth in favor of Persona because there are just too many advantages. The user might already have an account, the flow is very good if they don't, it takes literally three minutes to integrate django-browserid (or whatever it's called now) versus skinning quite a few templates for all the login and reset forms, it saves the user from having to remember yet another password, etc etc.

I couldn't be happier with a signin solution. It even complements my legacy solution very well, you can see a demo at http://www.yourpane.com (click "Persona", never mind the email field.)