Somewhat along the lines of your focal length and mirror discussion.....You guys have any comments on the effect of focal reducers on Schmidts?  Should allow you to have, say, an f/10 scope and, in effect, an f/6 too.  Flattens and widens the field allowing some deep sky stuff, with a scope still able to do average planetary work.  I know a schmidt isn't a compromise everyone is willing to make but...and remember, I am a rank amateur and will quit this list in a huff if you say bad things about Schmidts.