I've always followed the break-in recommendations on my cars, but I've seen first hand that the manufacturer's themselves don't exactly baby newly manufactured vehicles.
I work for a company that designs automotive manufacturing facilities and have been to numerous plants, including Honda, Toyota and Ford. It is standard procedure to drive each vehicle off the end of the asembly line, and onto the test track, where the test drivers boot it at full throttle to the end of the track (about 1/2 mile) and slam on the brakes hard enough to kick-in the ABS, in order to identify any defects. I've always wondered why they ask their customers to baby the vehicles when they've already been driven hard right off the end of the line.