something similar to what is provided for the single client instance.

While it's certainly possible to arrange for all clients to backup to a common area (on a network), the machines, particularly laptops, may not be connected to the network, or on at all, at any particular time. The Server, on the other hand, is basically on at all times.

I understand that to back up to a network location, the service will have to run under a network account, rather than as "System", but this is fine.