The important feature difference is obviously not the processor.
This means TSU9800 is not having a better frame rate.

I can´t believe the limitation are caused by the firmware. If yes, it would be nice if next upgrade is solving this. Today the processor is cheap and shouldn´t be the reason for limitation either.

I´missing: Processor? / graphic performance for image streaming
WPA2 (planed for this year)
TSU9600: scroll wheel (like TSU9400); next genration comming; this year
WIFI N standard (300Mbit)
sound streaming, mono is ok