I've done some subsequent searching and found "some" information that agrees with your post -- I could not find anything more technical on the system beyond the fact that it standardly provides nearly all power to the front wheels and a small portion to the back all the time. So you are correct in that it IS AWD all the time. I found another article that quoted a GM engineer that talked about the reprogramming they had done with the system to all it to more closely mimic the SH-AWD of Acura, driving the outer wheels with more power around corners -- but it didn't specifically state they could do this wheel-by-wheel, which apparently the Acura system can do. The GM system under most circumstances will provide most of the same advantages.
It's interesting that you have far more detail in your Canadien brochure -- also that the system disables when the spare is mounted -- this is EXACTLY the same as the versa-trak system and I believe it still has the same basic mechanicals driving the AWD system. It's the programming, additional sensors that's different.
My concern for this AWD still holds -- we had recurring noise issues in the rear gerotor drives on the rear wheels, only solved by a very expensive flush & fill with special synthetic oil. The next step, we were told, was replacement of the mechanical part -- which, when not under warranty, is very expensive. I believe the same mechanicals are driving this AWD system.
But in the end, I guess someone's need/desire for AWD would have to be outweighed by the assurance of traction under almost any condition. I can tell you we never, ever got stuck or had issue with the traction the system provided under any conditions we encountered in the midwest.