The thing is, truth-in-advertising laws are a tricky thing. The laws are written under the premise that most comparable products are of about the same quality, so any company is allowed to call its product "the best". But, if a company wants to say it's product is better than another company's product, that statement must be the truth to be legal. So Apple is fine saying "Fastest Personal Computer", but not okay saying "Faster than the AMD64".
It pays to know your laws.