Buddypress vs WPMU social Plugins

Does anyone have a decent comparison or summary of a Buddypress setup vs. the WPMU Plugin's suggested by wpmudev for setting up Edublogs style service?

Plugin's in question:
https://premium.wpmudev.org/project/friends
https://premium.wpmudev.org/project/communities
https://premium.wpmudev.org/project/messaging
https://premium.wpmudev.org/project/forums

I've already got my WPMU site installed and had already installed BuddyPress and the builtin forums to it, but as far as I understand that only affects the main blog site, not hosted sites?

The four plugins above were recommended for a Edublogs hosted type service, but I wasn't quite sure why they're being recommended over Buddypress, what features may be lost or gained.

Any help on this would be greatly appreciated by anyone with experience in the two.