I think Alpha Audio inadvertently made the opposite case. You need to have independent third-party testing to make sure the product you're buying at least matches manufacturer's published specifications. If the manufacturer provides none, then it should be tested and measured to ensure it's at least designed properly and functions as expected.
The measurements performed at ASR, Erin's Audio Corner, Stereophile, and SoundStage Hi-Fi (to name a few) typically use a consistent method for obtaining those numbers. In that case, you can compare the performance using those measurements because you know the measurement parameters.