The total peak to peak error is just under 10 arcsec's, with no Periodic Error Correction, very good for a mount in this price range. The result should even better with the Gemini Level 4 PEC applied. Instead of the desired smooth "sine wave like" curve, this worm gear has two peaks with three valleys, with a few bumps along the way. This is all easily corrected with auto guiding.

Improvement may be achieved by swapping the DEC and RA worm gears. Also, one can buy a new gear for $50, hoping to get lucky and receive a really good one. Another improvement is to use higher precision bearings.

This mount is no longer used for deep space photography. I just use it visually and for planetary and lunar photography.