Audi Quattro Vs BMW Xdrive Vs Mercedes 4matic

Do we have a non bias comparison (or technical fact) between these two? I owned X5 before and they used more AWD propaganda than MB and Audi. I was invited couple time to their driving events to see the car in incline roller vs. lexus... to demonstrate the superior BMW xDrive system. But they did not put the MB because they said it will work too...
I love BMW Xdrive system and my current W212 4MAtic. In BMW, you can feel it when the system is working... it vibrates like hell... The MB just very smooth and probabaly a blink of Yellow triangle.