They are electrically equivalent. If you had 4 lines, the signal would be split in 4 either way (either a 1x4 splitter for individual runs, or 4 "Y" splitters at each location). The run length would be the same as well.
The run length would NOT be the same. If the run was 25' in 4 different directions it would still only be a 25' run. If one run went out from the AVR and then connected at each point, the place at the end of the run would be 100'. I already stated that I do not believe that there would be a signal loss using coax but I don't know that for a fact. But why take a chance on extra connecting points and extra length in the run.
Daisy chaining multiple subs sure would work. I guess you would just need to make a connection if you have to send one sub out for repair of if you decide that a sub doesn't work at a particular location.
Bottom line is either way will definitely work. For me, I know what I would do.
