Optimum is my all time favorite protein as far as taste, but i have been using Protein Factory for over a year, and i am bigger and stronger than ever, so i know they have legit protein. As far as taste, it doesnt tast as good, i usually order 20lbs. of chocolate sweetened with splenda. It is very sweet,and not as tasty as optimum, but i am one of those guys who SLAM the shit quick, clumps and all, so taste isnt really that big of an issue for me. Price IS an issue, and i can get 20lbs. of whey from Protein Factory for $84.00, and i only get five pounds of optimum for about $40.00, no contest there for me i will go with protein factory, cause i aint a rich man let me tell you. So i give a not to the Factory.-WULF