The plugin installs easily and does create user accounts that are associated with their Facebook accounts. So, if that is all you are looking for, I don't think you will find a better plugin.
However, there is a serious flaw that, based on Justin's blog comments, has yet to be addressed and no one has found a resolution for.
When it creates the user account, it uses a unique FB id for the username and Nickname (e.g., FB_99999999) while inserting the users first & last name appropriately. But, when you try to access that user directly (Profile, My Account, etc) WP fails and returns you to the home page. This does not happen with user accounts that are created in the default fashion.
I personally am trying to find a resolution, but it is frustrating, because I want to support Justin's work. So, just be aware of this issue.