I got a brief period of clear sky a couple of nights ago. Less than an hour, but long enough to make a measurement of periodic error. To keep things fair with my pre-mod measurement, I used the same camera, scope, and software combination with all the same settings. I was using my DMK21AF04.AS CCD camera in the Celestron C8, with drift logging through K3CCDTools. Clouds started rolling in but I got enough data to plot in PEAS. Below is a screen shot from PEAS, and you can see that the "Max PE" values indicate a PE of a little less than 10 arc-seconds peak to peak. This is half of the pre-mod PE value. I'm pretty happy about the improvement - this is about the performance level of mounts costing twice as much or more. I'll keep on testing as weather permits.