Mark,
I think you made a good choice with the 9.25. I wish my wife would let me get one! But I can't part with my other scopes, yet!
Personally, either material would be ok, but the carbon fiber has the advantage of thermal stablility. Here's what Celestron says on their website (or used to!)--
"Carbon Fiber Tube — 1/4 the thermal expansion of aluminum which creates a more stable focus. The Carbon Fiber tube is 4 times more resistant to temperature changes than aluminum tubes, thus minimizing your need to re-focus."
I think you made a good choice with the 9.25. I wish my wife would let me get one! But I can't part with my other scopes, yet!
Personally, either material would be ok, but the carbon fiber has the advantage of thermal stablility. Here's what Celestron says on their website (or used to!)--
"Carbon Fiber Tube — 1/4 the thermal expansion of aluminum which creates a more stable focus. The Carbon Fiber tube is 4 times more resistant to temperature changes than aluminum tubes, thus minimizing your need to re-focus."