@PaulS First arg is #step/rev, 2nd arg is motor one or two. (the pin configution is hardwired as it is a shield)
@66harley, original poster: I notice you have two stepper libraries - you use the AccelStepper library to implement the acceleration profile which uses the AF library to do the step. "Interesting".
The AccelLibrary works if you call runSpeed in the loop() - which you do - but it must be called "as frequently as possible" (quote from the AccelStepper .H file). In your loop() you have a delay(1000) which means the runSpeed() is only called once a second. Hence the fastest your stepper can move is one step per second.
Do not use delay(). Wrap the code that must only run once a second with a timer routine, like the example "blink without delay" and/or read Avoid delay and/or read Blink two leds without delay. Did I give the impression that using delay() is bad? Yes? Good.