The DeVille is smooth and stable at high speeds. The steering is precise and direct, so the car always goes where the driver intends.

The DTS model is particularly agile and feels rock solid on the open road. DTS gets the latest version of Cadillac's Continuously Variable Road-Sensing Suspension (CVRSS 2.0), which features transient roll control, lateral support and enhanced stability. This electronically controlled suspension adjusts shock-absorber damping every few milliseconds, adapting to the road surface and the driver's demands. Variable shock damping allows the DTS suspension to soak up road irregularities and isolate passengers from the outside elements, while still providing the tight control needed for precise handling.

Braking is sure, stable and effective, with nice firm pedal feel. DeVille's braking system combines large four-wheel-discs with a small, lightweight anti-lock system. ABS works very well on this car: Jam on the brakes and you still have control of the steering. Just remember to steer. Electronic brake distribution (EBD) helps reduce stopping distances by re-proportioning the braking force from rear to front as the vehicle stops and its weight shifts forward. In everyday, around-town applications, the brake pedal feels smooth and progressive, making it easy to slow the car down smoothly.

All DeVilles come with the superb Northstar V8 engine. This engine is tuned to produce 300 horsepower in the DTS, 275 horsepower in the DHS and DeVille. Thanks to this highly refined power plant, the 2003 DeVille is responsive, quiet, and fuel efficient. The DTS has lots of power and growls aggressively under hard acceleration.

The DeVille has a great drivetrain. The automatic transmission uses a viscous converter clutch for maximum smoothness with fuel efficiency. We were particularly impressed with the calibration of the transmission, and with the way it communicates with the engine. Squeeze the throttle to the floor in many new overdrive-automatic cars and they surge briefly in fourth, then downshift abruptly into second, an annoying process. But not the DeVille: It shifts immediately but smoothly down to third, snatching that strategic position in traffic without upsetting your passengers or your piece of mind. Slam down the gas pedal and it downshifts smartly to second, the V8 growls and the car rockets ahead. It all works wonderfully.

Electronics help the driver control the DeVille in emergency maneuvers. Cadillac's StabiliTrak 2.0 skid-control system (standard on DTS, optional on DeVille and DHS) makes it nearly impossible to lose control of the DeVille. We say "nearly," because nothing can save you if you break the laws of physics. However, we reached some very high thresholds in the DeVille without breaking any of nature's laws. On a closed circuit, we were able to steer into a turn very abruptly, trying to spin the car out. In situations that would have caused most vehicles to pirouette into the weeds, the StabiliTrak-equipped DeVille held its course wherever we steered. StabiliTrak's computer lightly applies the brakes to individual wheels to keep the DeVille in control. This type of system can be a godsend when you are surprised on strange roads or caught out in emergency traffic situations.

Cadillac's Night Vision infrared system ($2,250) is available on DTS and DHS. Using the same technology as military infrared systems, Night Vision makes it easy to see wild animals, pedestrians, and whatever else might wander into the road at night. More important, it allows you to see them when they are still far down the road, past the reach of the headlights. In theory, Night Vision can greatly enhance safety. Here's how it works: An infrared camera mounted in the center of the grille transmits an image about the size of the rear-view mirror onto the lower portion of the windshield. It's sort of like the heads-up display used in fighter aircraft. The image position is adjustable; it can be raised or lowered, and its intensity can be changed. Having Night Vision displayed in the lower area of the windshield requires some adjustment, however, and we think it could be distracting for some drivers. It's probably best to glance at it occasionally, they way you glance at your gauges or rear-view mirror, to see whether your path is clear, or if any critters are lurking in the bushes. You would not want to try to drive just by watching the Night Vision screen; it would be like trying to drive by watching a television monitor. This is a promising technology, but you should take a good look at it to determine whether you'd find it worth the considerable extra cost. You can tell when a DTS or DHS has Night Vision by the grille sensor, which replaces the Cadillac wreath and crest.