Pretty much this - the same with bells, too, they can be "tuned" differently. I find a lot bigger differences between same-sized bells than chimes, though. I think the computer controlled aspect of the chimes gives it a different tone too slightly. Maybe it's just the rhythm/pattern being controlled by the MPU board rather than the score motor.

I remember hearing that because it pulses so fast that it kind of "levitates" the plunger instead of hitting, so only the first note is heard because it is the only one that starts dropped down all of the way.

You buy the EM Unless there's a specific fix that can make the chimes operate smoother it's probably just a thing of the breed of those early SS games that still use chimes that comes with owning one.

Not as fast as the MPU pulsing those chime coils