Hi Rick,
I think I recall seeing the takeoff tables in the CJ2 going to 9,000 ft and the max takeoff altitude as 10,000 ft... Even with a turbine - you may have to pay attention to density altitudes and focus on launch times that play to your favor...
I'm very new to biz jets though - so take what I said with a grain of salt...
As I may have mentioned - I'm one of Carenado's biggest critics - however - the recent CJ2 seems like a pretty decent plane and if they follow through with their responses to me via their ticket system - they seem to be addressing most of my gripes... I don't have the GTN750 - so I am basing my comments on the default aircraft and FMC...
Regards,
Scott