Not very familiar with librevault, but on a cursory glance the design seems fairly consistent (p2p, encryption, offline support).

However, Dat has put a lot of focus into developing an ecosystem to build applications on top of the protocol. This is making awesome things like Beaker Browser[0] and peer-npm possible [1].

[0] - https://beakerbrowser.com/ [1] - https://github.com/noffle/peer-npm