Cadillac's Seville has been known for years as a potent and appealing road car. The new STS builds solidly upon that reputation, adding a stylish exterior and ample technology.

Smooth-riding and well-controlled on good pavement, the STS isn't especially troublesome on rougher patches, either. Steering with a light feel, the sedan comports itself neatly on wet pavement and yields confident sensations.

Unfortunately, the ride was worse in an STS with Cadillac's Magnetic Ride Control system. When rolling through broken or lumpy pavement, that AWD-equipped sedan version felt less confident than a standard model. All-wheel drive enhances driver confidence on slippery surfaces but isn't particularly evident otherwise.

Because the V-6 engine delivers plenty of zest, there's not much need to move up to the more powerful and costly V-8. Automatic-transmission shifts may be heard, but they're typically not felt and barely noticed.