I'd say that everyone is right and no one is wrong about clay-barring your new car. The contamination on the paint is minimul on a new car (normally) and if you're good with a buffer then spend the time and do it all but if your not carefull, you could add to the problem so just take your time, find some threads on how to clay-bar and buff a car and be carefull.
www.premiumautocare.com has some good info and tips + products.