Flash 9.4 is much heavier and needs beefer systems- in effect, its not designed for handhelds. Flash Lite is designed for the minimal resource needs of mobile devices, and hence why it works so well. Really, Flash Lite should have been the natural evolution of Flash all over, but hey, Macromedia/Adobe made decisions for whatever reasons.
I think performance will always tie back to the device just like it does on the desktop (if you have a slow computer with no Ram, any version of Flash will seem sluggish). I'm sure Adobe will work with OEM's to get flash 10.1 optimized for certain partners, after that there'll probably be baseline device requirements in order for other devices to have well performing flash.