AstroTech has an f/9 6" for around $1,300 and an f/9, 8" for $3,000. Anyone heard anything bad about these? I've been pretty impressed with AT's products so far... my AT80ED APO is pretty nice for the price and would make a good guider for something like this. I've heard that collimation can be a problem with RC scopes. Any experience with them?