I have been in the hobby for two years now. I have a 10" truss dobsonian that I built an VNS style equatorial platform for that is powered by one of the common equatorial motors. My experience with this setup has been great and I have even been able to take decent pictures of galaxies and small planetary nebula.
I recently purchased a dedicated astrophotography camera and started learning about the EAA tools and autoguiding. I have searched through the forums and it seems that the standard is to use a pulse guiding method where a software monitors a guide star and sends pulses to the mount to either speed up or slow down as the guide star drifts. This seems to be an extension of the hand controllers people use to move East or West (I'm only considering RA axis for now) to keep objects in the FOV. My understanding is normally the mount has three speeds (West, Sidereal, East) and when there is too much drift, the pulse guiding software will send a direction and a duration that it expects will bring the object back into the FOV.
I'm curious what the benefits of the pulse guiding method are over a variable rate method. Do variable rate guiding softwares exist? ASCOM drivers seems to support it with the TrackingRate and RightAscensionRate offset properites. I am writing my own ASCOM drivers to control the motor on my platform and I was wondering how a variable rate method with a PID loop would compare to traditional pulse guiding. I was thinking take the error measurement from the star drift at a periodic rate (1 second or less) and apply to a PID loop that sends a control output to the motor in the form of a PWM duty cycle percentage. There would be no more pulses, just a control output percent that is sent to the mount periodically.