I don't know the specifics, but it's a pretty good rule that the larger the motor, the slower it's max usable speed will be.
With the same drive and voltage, a 200oz motor will spin much faster than the 381oz motor will.
I've heard of people using 200-250oz motors on small mills at up to 2500rpm with a G540. For a 381 oz motor, your max rpm will probably be around 1000 rpm. The 570oz motor will be slower still.
Using steppers for high speed applications can be problematic. Because steppers have the most torque when they are not spinning, you need to keep them spinning slower to get the maximum power out of them. This limits your resolution. When you need to slow the stepper down to move the machine faster, speed becomes inversely proportional to resolution.