The ATS-V coupe marks when the Cadillac ATS lineup found its look. To me, the regular ATS sedan is decent looking but not as interesting as the current- or previous-generation CTS sedan. As for Cadillac coupes, I've been hard to please. The regular one is too bland, though I've also criticized the CTS coupe as going too far - slab-sided, and with a rear end that's also a bit slabby and whose boat-tail shape is trying too hard.
The V-Series treatment certainly makes the new 2016 ATS-V sedan look more interesting, but it's on the ATS-V coupe where the flared fenders, more aggressive nose and tail, and the various cooling and aerodynamic changes bring the canvas of blandness to life.