You bring up a good point..
your not 'STUCK' with any particular protocol...
your system can implement ALL of them at the same time...
so, Go with your gut..go with what suits you.
if it happens to be PLCBUS, great. if it happens to be CBus, all the best..
My point, coming from an integrator of HA stuff..
is that PLCBUS is almost done, and I don't know what's next.. so many protocols, so little time..
I think there is a need to redo X10.. make it bidirectional... and in Ruby.
Whether that is before or after protocol X and Y., no clue. (my head is so wrapped up in OO world)