Quick question:
Does nMaxRegulatedSpeed proportionally decrease motor speed?
As in, will

run at 50% speed or at 25% speed?

The nMaxRegulateSpeed command regulates the maximum encoder counts per second used in the PID algorithm for the LEGO NXT motors; the best resource for this is on our wiki, which can be found here http://www.robotc.net/wiki/NXT_Motors_a ... er_Control

As you change the value using the nMaxRegulatedSpeed command, you are telling ROBOTC what the maximum encoder counts per second should be used instead of the default of 1000. For instance, setting the nMaxRegulatedSpeed to 750 will result in a motor power command of 50 to spin the wheels at 375 encoder counts (50% of 750) per second.