So I think I may have made some progress. As I mentioned, I was able to get a good calibration earlier, but the numbers were still suspect as well as the guiding graph. I checked the subs I took tonight and sure enough close to half of them were garbage (oval stars). This was with trying PEC enabled and PEC disabled. Why couldn't I get good subs without PEC enabled on 60 sec subs???
So in desperation (frustration) I went ahead and tried to do a new PEC curve using PEMPro v3 (why aren't there any tutorials for this software??). I read through the help file as I tried to run the curve and eventually wound up with a new PEC curve and uploaded it to the mount (with fingers crossed as I had no idea if I did it right or not). I don't find the help file to be all that intuitive, especially when they start talking about X this and Y that....what the heck??.
Anyway, I ran PHD2 and so far the guide numbers are better - but most importantly - the stars are round in all the subs (10) so far. Still too early to officially celebrate - but there is hope.
I guess I'm going to plan on doing a new PEC curve every 3-6 months, if this proves to be the issue . Don't think theres any harm in doing that and I may actually eventually get comfortable with that software???