Networking/Multicasting has two advantages over USB.
1. It can image multiple computers at one time.
2. It transfers at the speed of the network.
Whereas with USB you can image one computer at the average speed of 40 mb/s with Networking/Multicasting the transfer speeds is that of the network. With a gigabit network that 1 gb/s. Plus you can do multiple machines. I believe Acronis TrueImage does have a Multicasting or Network Imaging solution but I'm unfamiliar with that software.