loksound "full throttle" issues, latest Athearn FEF3 release (December 2017) - Model Railroader Magazine

Randy,
You're right, it's not the same as manual notching; it's worse.

I met Matt at the 2016 NERPM meet in Enfield, CT and he showed me the Full Throttle feature on his demo track (approx. 8 feet long).  Then he allowed me to try it.  IIRC, this is what happens: you hit a button and disengage the motor control and engage the Full Throttle feature.  You turn the knob to rev up the sounds, then you hit the same button and go back to motor control.  Turn the knob and the loco starts moving.  To make more revs, you hit that button again and go back to sound control (disengaging the motor control), then hit the button again to go back to motor control to adjust the speed.

To slow down, you hit the button and go to the sound control that disengages the motor control, turn the knob to drop the sound rpms, then hit the button and go back to motor control to slow the speed of the loco.  And so on.  It doesn't sound easier to me.  In fact, it sounds a lot harder.

What I really, really don't like is that you can spend an awful lot of time running your engine without actually having any control of your loco at all (other than the sounds).  There's been far too many times that I've witnessed fellow club members and myself run into trouble when you think you have control and you really don't (the "I'll accelerate out of the yard here and oops, forgot to throw the mainline switch...").  I can only imagine a bunch of trains running on the layout where half the time they don't have speed control because they're fiddling with the prime mover RPM's.  It's a wreck waiting to happen.