While Cadillac awaits a return to the "standard of the world" status now claimed by the likes of the Mercedes-Benz S-Class and BMW 7-Series, it has introduced a new full-size luxury sedan for the 2013 model year, the Cadillac XTS. The XTS is a front- or all-wheel-drive sedan, intended as a replacement for the former DTS four-door. Derived from...