A sharper sword in the form of a twin-turbo V-8 has been pledged to the CT6, and hints of an even larger and more majestic Cadillac built off the same new platform continue to circulate. But for now, this is it: a handsome four-door with a four, a six, and a turbocharged six that acquits itself well as a sports sedan that just happens to have a bigger back seat and five more inches of corresponding legroom than the CTS. It will certainly sit atop GM’s luxury throne for now; the Platinum-spec car we drove carried a sticker north of $88,000.