I keep both axes out of balance to improve autoguiding. RA to the east, dec doesn't matter so much. This keeps the worm in constant contact with the toothed wheel and pretty much eliminates any backlash from the system when minor adjustments are made. If it is in perfect balance the scope will wobble in the worm with changes direction.
I was taught that as a kid in the 70's by the chap that built the mirror for the AAT. Very old school, but I still recon he was right
