@ Nick S
The Login extension was being requested by others that wanted a “Connections” solution. It wasn’t something I planned on, but I got enough requests for it so I took an afternoon and made one. Previous to it I would just point the users to the many freely available login plugins.
You already have a login solution via the membership plugin, so, no, you do not need the Login extension.
Hope that helps clear up why you would/wouldn’t want to use it.