Hello!
Sorry to double post but yours crossed with my last.
Two interesting points.
As far as I am aware not many of the G1000s rolled out at the moment incorporate Garmin's autopilot - if any? Certainly in the 42 the autopilot is a "standard alone" unit in the case of the 42 a KAP140 with alt preselect. The autopilot takes its nav information from the G100 but in all other respects will operate stand alone. In short if both displays failed or the GPS component failed the autopilot would still maintain wings level, climb, descend and hold and maintain a heading. I have to admit I am not sure if it would fly a coupled G/S approach - probably not because the frequency is fed from the G1000. I would agree that presumably all of that will change when the autopilot is integrated.
In theory you still have a radio because if the radio and the displays fail the frequency reverts to the emergency frequency.
I think however it is important to understand how the G1000 works. At least as I understand it each component is effectively a modular element so the GPS feed comes from what are almost two G400s, the avionics stack in the back of the aircraft contains two rack comms units etc. The whole lot is integrated via the AHARS - perhaps there is an arguement this is a weak link, and I am not sure how much redundancy there is, but that aside I guess it is no more nor less likely than the G400s will fail behind the G1000 that when these are separate units on the front panel.
I particularly like the fact that with the G1000 in the event the primary display fails all the vital information can be switched to the right screen whereas it is my understanding if that happens with the Integra the right hand unit is not capable of displaying any of the primary information.
Moreover the Integra seems to be to be far less intuitive than the G1000.
Finally with the Integra I am not certain of the systems ability to recover after a power failure (you may well know the answer) where as the G1000 will recover attitude and heading.
At the end of the day perhaps horses for but it is interesting discussing the respective pros and cons and sorry for the thread drift.