From what I've found while poking around in different threads:
- removing the nag screen (as pointed out by you)
- updating older versions 920/930 to 940 software interface and maps (may not be of interest for you but great for those with older head units)
- adding a safe-mode setting that allows for selective (software) bypass that can be turned on and off
- modifications for other continents (US->EU, etc.)
The only thing I miss for this unit and software is album arts for mp3s if you don't have an ipod. Most other units (not from pioneer though) have this feature for USB devices or SD cards ... too bad, for an otherwise nice interface ...