This site does say that RC scopes are inferior
http://www.astrooptik.com/Komplettgeraete/Cassf9_e.htm
You can order the cassegrain with an F3 prime focus option as well. Now that would be VERY nice.
What Id love to do is put a cooled 450DSLR onto one of those scopes pick a good object and get around 3 hours of data on it. Actually If I could afford a scope like that, Id have a Canon 1DSMK3 specially modded, all 25 megapixels of it. Id need to set aside a few more grand for a quad core workstation to process the huge images though
Scott