I have both. One thing to note for simplicity is that the 10X has Aux 4 and Aux 5 as rotary knobs. Assignable to any channel you wish.
The convenience is that if you have your nosewheel steering setup as a seperate channel, you can easily trim it for straight steering with the knob without affecting rudder trim. The 9303 has no knobs and complicates it as you have to go into subtrim menus to adjust for centerline tracking. Otherwise if you use the sliders they can be easily bumped. Just an inconvenience really. I prefer the 10X though for that reason among others.
BC