So no digital stuff mixing in it appears. And certainly not a TV set. So it's somewhat pure.
That seems to be the main argument for having multiple dedicated circuits. In the first thread I pasted, MC doesn't subscribe to that logic. In the second thread, Eric Squires suggests one circuit but with a device to isolate digital. (I haven't done that yet.) I had thought that having separate circuits would better isolate them, their power draw, from one another. Again, MC refers back to what they all share in common--the neutral/ground bar at the panel.
I don't have a good enough grasp of electricity to understand the theory involved, but I do feel I recognized an incremental improvement when I put all four of my components on one duplex.