I've driven the CTS-V on the track as well.
Luckily I got my hands on one of the few manual CTS-V's at the event. The car has insane amounts of torque. The first time I did the 0-60-0 test I unintentionally did a burnout trying to launch the car. The next time I feathered the throttle all the way through and pulled off a really fast launch.
It's a great car, good brakes, good handling (for it's size) and tremendous power. I was able to drive the coupe and sedan, not much difference in driving demeanor from what I remember. I drove the coupe on the road course, it handled itself very well for a 4,000lb car. That's exactly what the CTS-V is, it's a big ass car that can haul ass and handles really well.
All I know is if I had one of those cars I'd be going through a lot of rear tires because it's just too much fun to launch that beast.
I'll be very very interested when the ATS-V comes out in another 3-4 years, if Cadillac can make the CTS that much fun I'm keen to see what they'll do with a car closer in size to a 3-series.