I just wanted to update you on my ETX set up. The ETX works great for this application, utilizing the ETX's built in flip mirror. Attaching the 201xt at prime focus and the 9mm ep in visual port. The ETX is parfocal at both visual ports, and so happens the 9mm illuminated and 201xt are parfocal too. It's as though this application was meant to be.
Lets just say less frustrating.
Well here is a pic I shot last night of M13. This 30 minute exposure shot on Kodak Portra 400 ISO, guided with the ETX and 201xt. The photo lab that does my processing gave me the roll to try. I've still to guide for longer than 30 minutes. I'll let you know how it comes out.