I am using the free WPMU DEV Membership Lite plugin. It was at version 2.0.7 but has been updated recently:
There is a new version of Membership available. View version 184.108.40.206 details or update now.
That is quite a jump in version number. Such a step may indicate big changes. I wonder if it is safe to update from 2.0.* to 3.4.* directly.
Has anyone made the update yet? If so, how did it work out?