Plugs seem to have fixed it.
Took it for a ten mile spin after changing yesterday.
No miss/jerk/whiplash at any speed/RPM, it's just completely gone.
Thanks for all of the info.
Sometimes, it's the little things that just drive you crazy! And in the overall scheme of things, plugs are just about the easiest and cheapest thing(s) to replace.
I was going to suggest you check the fuel pressure regulator. The regulator is vacuum controlled and there is a diaphragm inside that can break. Ethanol in the gas usually accelerates the process of degrading the rubber. Then the vacuum line is sucking in gasoline, piping it to the intake manifold, which screws up the mixture. When it happens, it usually causes a hard start (extended crank) and rough idle/rough running at low speed.
