As above when you are pedaling above 15.5 mph when the motor is no longer assisting you the extra gearing inside the CX motor creates a bit more drag than the cogs inside the active line. Even though the motor is now not powering, you still have to turn those cogs and the motor because they don't disengage above 15.5 mph.Please feel free to enlighten me!
I'd buy the active line anyway because it is less complicated. a newer design and it will take you further on a given amount of battery power compared to the CX motor.