I remember years ago (about 60 years!), I got to ride in the cab of a FP7 or 9 with an Alco (RS-10 probably) behind it for a passenger train power. Every start, got a 'bump' from the Alco unit to the emd unit. The engineer who took me along with him told me the Alco didn't start as smooth as the EMD units.
Also for what it's worth. I use the Bachrus speedometer, and have found the Soundtraxx (TSU-1)? units best match TCS decoders (steam versions) unison?the Exponential 2 speed?curve in the speed tables.
