I seem to recall needing an asbestos suit when I suggested (albeit brazenly) :
1) accurate mount/guiding/self guiding/AO guiding.... first
2) optics..... a long second (corollary: you know you have a really good mount when you can see problems with the optics)
I suspect the RC is OK. But due the very large secondary for the aperture probably would have made a different choice at that aperture.
I also suspect you will will find imaging nirvana with decidedly better tracking.
Stick with it
