After some research, it seems like the 300SD had far fewer "sensors", "relays", and "troublesome" items that may go bad than the SE does. Seems like there are so many more things on the SE that can go wrong when comparing to the SD.

Just how much more "complex" is the engine electrical on the 380SE compared to the 300SD, or is it my imagination.

Seems like another reason I would want a SD over an SE, even though I am told that my electrical system (engine and otherwise) are in perfect order (so far).