rgbrock1
I'm a software engineer rather than a pilot, so a s/w based answer.
On handover the pilot may be provided with a less functional plane than normal.
However, this is because the s/w has 'seen' events that [its designers feel] prevents it from reliably providing the 'lost' functionality.
So your wording of the question was very pertinent. Is it 'more desirable' to have full [but untrustworthy] functionality or a more limited [but trustworthy] functionality? AB have naturally gone for the latter.
Regards, Peter