Autozone or Napa Echlin, Quality?

Standard Motor Parts is now a major component supplier of ignition and switch/relay parts to Echlin, who reboxes them. Standard used to be sold under the Blue Streak line of ignition/electrical auto parts. I worked for a while at a NAPA store where some of our part numbers came in mistakenly packed in Standard Motor Parts boxes; both Echlin and SMP parts are of good quality, but Auto Zone ignition/switch/electrical stuff I use only when absolutely necessary.