AST Sports Science was the first nutrition company to introduce the benefits of whey protein in 1993. Since then there have been many imitations. Some good - some bad. The difference lies in the proper manufacturing techniques required to deliver a finished product that exploits the unique advantages whey protein has to offer. Screw up on any part of this process and you might as well be taking cheap soy protein.
Protein is a durable nutrient, yet quite fragile at the same time.
Whey protein in particular is quite sensitive to several controllable factors - like heat and acid. The problem here is that most whey manufacturers use both of these factors to process their whey protein into an end product they then sell to you. Bad - very bad. Protein is processed under very delicate and critically monitored conditions designed to not only maintain protein integrity, but also to enhance the natural effectiveness and bioavailability of the whey fractions beyond their natural state. This is something no other manufacturer does.