Overall, the Lucerne proved to be a spirited car along the not always smooth roads, even at high speeds. The Lucerne handled with aplomb, exhibiting no wallowing or causing any untoward moments. A rigid chassis is the key to balance sharp handling with a smooth ride, and the new Lucerne really delivers.

The Lucerne's ride is excellent, thanks to the long wheelbase and stiff body structure. In back-to-back driving along a stretch of less than perfect road, we found the Lucerne's ride quality comparable to that of the benchmark 2006 Toyota Avalon. Buick loyalists who are used to a cushy ride will not complain about the Lucerne. It might be stiffer than they are used to but it's still plenty smooth enough. And the steering is precise and responsive.

The CXS features GM's Magnetic Ride Control, a sports suspension designed to enhance overall ride performance. Magnetic Ride Control uses magnetically charged particles suspended in a synthetic fluid to continuously adjust the fluid's viscosity to varying road surfaces and driving characteristics. The system, which first appeared on the sporty Cadillac XLR and then the Corvette, delivers a quicker response than conventional valve-damping systems. We tried a CXS with the system and found it did handle better but not significantly.

Indeed, when we tried a CXL V6 we were pleasantly surprised at just how well it performed. With the lighter V6, the CXL seemed more agile on twisty roads and the front end felt a bit lighter. The V6 models also suffer less from torque steer, a slight tugging felt through the steering wheel when turning and accelerating at the same time.

So which model? If you don't require instant power when accelerating away from traffic lights or merging onto freeways, the V6 model is probably a better bet because it costs less and gets better fuel economy. We were pleased with its performance. However, GM's excellent StabiliTrak electronic stability control system is available with the V8 models, which improves driving control by reducing the chance of skidding. StabiliTrak is well worth having.