They are a bugger to focus. I never got RoboFocus to work on mine (lack of trying). So, I just used to do it by hand with the assistance of the Bat Grabber software.
Once I move to Caloundra, I will have more time to set it up properly.
I am not a visual person, but, I have also looked through the FSQ-106N with the 1.6x Extender-Q. It is really quite something.
H