Host Jonny Lieberman doesn't just look at dynamics. He starts off with an assessment of each car's interior and its infotainment interface: CUE on the Cadillac, COMAND on the Mercedes and iDrive on the BMW. A bit of a spoiler, CUE doesn't fare any better here than it did with Consumer Reports, for essentially the same reasons. Thankfully, the ATS has tricks beyond its touchscreen.
The victor and the overall ranking might surprise you. One of the contestants "goes around corners better than it goes in a straight line," one of them would have won the comparo if it were held a year ago, and one earns more mention of the word "rubbery" than you'll hear outside of a Kumho factory.