I tried the following this morning.
Start the car normally, drive the car warm, then i deactivated the AS&G function and let go the throttle so i let the car brake with the engine, but i felt just normal. I tried it a few times, both on a even level road and when i where driving down a hill.
Then i tried again with the AS&G function on(not on the same hill, but at a similar steep hill and with the speed) and it felt just like normal.
But when you turn on the AC (i did not try this, this morning but have tried it some time ago, i mean we have a thread describing this "Feature") you can feel how the AC pump slows down the car..
So if you drive in a steep hill area and want to save some brake pads, gear down and turn on the AC when going down a hill
and kill it when driving up again, this way i assume you use the engine the best possible way as a brake.. (But i also think, that it's a bad idea to turn on and off the AC all the time, because it can't work well that way...)