I don't think there's any objective way to define "most advanced" -- it just means "best." Their marketers claim the new OS they made is the best OS. If there is some aspect of the OS that is considered the best by someone, they're not wrong. If there is some aspect of some other OS that is considered the best by someone, they're not right. From your BBB link, see "puffery."
As other examples: they say the demand for the new phone is "incredible," they've been working "hard," the phone is "completely" redesigned and "blazing" fast, Macs are "the best" personal computers in the world, and that Apple "leads" the digital music "revolution".
If you feel the need to define quantifiable standards for some or all of those words, please do so -- it's the same motivation that drives people to get philosophy PhDs. But understand that you will be neither right nor wrong because those terms are subjective (and, word to the wise, if you get a philosophy PhD your options for professional employment will be limited).
As other examples: they say the demand for the new phone is "incredible," they've been working "hard," the phone is "completely" redesigned and "blazing" fast, Macs are "the best" personal computers in the world, and that Apple "leads" the digital music "revolution".
If you feel the need to define quantifiable standards for some or all of those words, please do so -- it's the same motivation that drives people to get philosophy PhDs. But understand that you will be neither right nor wrong because those terms are subjective (and, word to the wise, if you get a philosophy PhD your options for professional employment will be limited).