Indeed, I'm thoroughly confused by the conclusion in #782971 - it seems the exact opposite of my experience just now with sane-utils 1.0.24-13 and systemd 224-1.
For me, I needed to modify /lib/systemd/system/saned@.service and set both Standard{Input,Output} to 'socket' to get saned working correctly over the network. This matches what I read in the systemd manpages and elsewhere for inetd-compatibility. -- - Gus