There's no denying the raw power and ultimate handling of BMW's 6-Series, but the model teeters on the edge of techno overload. Electronic add-ons for the steering, braking, and suspension take away some of the feel that makes sportscars emotional purchases--and add heft and confusion to the car. A good diet, kicked off with a trip to the recycling bin for some of the electronics, would help the 6-Series regain some sportscar luster.