It has taken 15 years to transform Cadillac from the retirement home to twin turbos, but good things are worth the wait. While the CTS and ATS have brought many German enthusiasts back to the USA, Cadillac has not forgotten the senior citizens. The XTS was refreshed last year, and it rides on the same Front Wheel Drive chassis as the LaCrosse and the Impala. We’ve reviewed both of those, and found them to be better than several imports in terms of power, efficiency and noise insulation.But GM has always saved the best for their top marque, and the new XTS is no exception. The magnetic suspension made its world debut on the STS back in 2002, and the latest version offers a very plush ride. However, if you choose sport mode, it instantly firms along with more steering feedback. The other obvious change is the display reconfigures into a giant tachometer and a full-size boost gauge. This is not a normal XTS.The XTS V-Sport has the same 3.6-liter twin turbo V6 found in the CTS V-Sport, and it is also the top engine option in the ATS-V. The only difference is that the XTS mounts the engine east-west instead of north-south. So engineers were forced to pull out some power to keep the AWD system reliable. Make no mistake, this is a big car. But it has 410 horsepower and 369 lb-ft of torque. The six-speed automatic transmission responds instantly to downshift and we didn’t notice any turbo lag.On a closed road in a typical Florida afternoon monsoon, we tried to get it ou...