Ray, 

You showed images of a mount with "40 arc seconds PE."  Assuming you ran a valid test it only demonstrates that PEC improves guiding if your mount has 40" PE.  I fully expect it would.  That doesn't begin to address whether PEC improves guiding on an AP mount with less than +/- 3" P-P smooth native PE.

Regarding guide logs... here's a copy of the email I just sent you - with guide logs from both mounts on Sep. 4 attached.  I can't imagine they'll be helpful - it's just one of the times I've enabled PEM and noticed no difference.  I can also provide you PEMPro logs from that same evening if such a thing exists.  I plan to do a proper and much longer test when the weather cooperates - possibly tonight.

--Email below---

Ray,

There was a lot going on this particular evening ... creating new PEC curves in PEMPro, running guiding assistant, testing various PHD2 settings, testing PEM on/off, etc.

These logs will be very difficult to draw any conclusions from since I had zero intention of making them clear and intelligible.  What I can tell you is:

PEM was enabled near the end of the night on one of the two mounts.  I believe it was enabled on the file that ends in 201308 but I don't remember for sure.  Total RMS stayed right around Total RMS for the other mount which had PEM disabled.  I also didn't notice a change from when PEM was off vs. on.

I will try and do a proper test tonight.  If there's improvement, that's what I'll report.  I hope there is.

Chad