Sorry, Vixen. Astronomy Technologies new line of Ritchey-Chretien astrographs has you beat! I placed my order tonight for the AT6RC from Astronomy Technologies along with a 66mm short tube refractor (sporting a 2" Crayford focuser) as another photographic platform.
The AT6RC is 6" f/9 true RC hyperbolic mirror design, with 1/12th wave BK-7 mirrors, and enhanced aluminum coatings for 96% transmissivity. Like the Vixen VC200L, the AT6RC mirrors are fixed, and focusing is external. Unlike the VC200L, this new RC scope is a true reflector, no optical lenses. For another $600 I could have gone for the larger 8" RC with dialectric coatings for 99%, but just couldn't bring myself to do it.
Should have some great experiences with this!