I went and looked. From what I can tell the activities are hard coded buttons (Watch DVD, etc) where as in the 880 you define your activities and they are selected by screen.
Note I don't have a 6xx I'm just going from pictures on how it appears to differ (so maybe some of this has other work arounds).
The screen looks a little smaller aside from not being in color.
I am guessing the programming is different since (if my assumptions are correct) the activities are hard coded. Well different slightly since it may be associate a device with an activity (or disabled if not) rather than define devices and then create activities to your definition.
That's my guess.
Note I don't have a 6xx I'm just going from pictures on how it appears to differ (so maybe some of this has other work arounds).
The screen looks a little smaller aside from not being in color.
I am guessing the programming is different since (if my assumptions are correct) the activities are hard coded. Well different slightly since it may be associate a device with an activity (or disabled if not) rather than define devices and then create activities to your definition.
That's my guess.