Gonkster:

There are some other things to add to your list that have me begging my master for a 990 instead of some steak scraps from the dining room table:

* RS-232 and USB upgradeability
* USB connection for computer audio playback
* Lip Sync Delay compensation
* A programmable trigger in addition to the "always on when the unit is on" trigger for the amp.
* other "stuff"

Down side:

* No green button.