It looks like there will be another benefit with FGU. Anyone with better than demo will be able to access their own characters while not connected to the GM (although they won't be able to use any content they don't own - but this is not that bad of a limitation because the info is usually copied to their character sheets in most rule sets). While this can be done in FGC, it requires the GM to export the character back to the player once the character has been brought into the GM's campaign.
I hope I have this right, but I think this is the gist of what Moon Wizard has been trying to explain on the Beta forums.