Well, the BIG difference is that multipath can be applied not only to mix currencys but general IP traffic of any kind, e.g. everything that uses the IP-protocol and all layer 4 (OSI) protocols.
So, if there was a way to transfer larger amounts of data between clients, then you could technically build a Tor-like network on top of the XC network? Does the XC network support moving larger amounts of data right now?