@MartyE and others... You don't need to make apologies for the Pullmor motors or lack of speed control. Everyone should watch closely at 7:19 to about 7:22 of your video. It does a lot to explain why I like Lionel's Pullmor motors and back-driveable gearing. It's not about going around the layout at a constant five scale mph (although I'm pretty sure your GE demonstrator could have run slower than you were running it in the video.) The initial movement between zero and 3 scale mph is just as important, if not more important to the illusion of realism. For you physics nerds, I refer to these as "precious moments." Surging from zero to 4 or 5 scale MPH (about when the speed control circuitry catches up) pops that bubble every time!
Here's another example that was shared by a different Forum member a long time ago:
https://www.youtube.com/watch?...list=WL&index=21
I'm pretty sure if you subjected our trains to lab testing with a stroboscope or high-speed camera, it would end any arguments on this subject. The initial movement on a dual Pullmor-equipped diesel like this one is better and more gradual than any diesel with two can motors except perhaps the recent Legacy / Liondrive, which also have back-driveable gears. The little Mabuchis and even Pittmans just don't get into the linear part of their speed-voltage curve until they reach about 800 RPM (which is usually around 8-10 mph.) In the range from zero to five and five to zero, the speed control tuning can sometimes make the motion more robotic and less train-like.
If you just want to turn your train on and let it run, then I guess none of this really matters. But if you like to RUN your train hands-on, switching, coupling, taking up slack, etc., a diesel with two AC motors will put a smile on my face every time! Thanks for sharing!!