Whey protein is something that people "whey" over think! (get it... way, whey... heh heh, I made a funny!)
Ive made perfectly good gains using ultimate nutritions 100% whey. I never noticed any sort of huge benefit using pure isolate, and in fact, the best gains of my life have been made usng good old fashioned Met rx MRPs!
Im not willing to pay twice the price for some nutrient profile that is 90% lab evidence and 10% or less real evidence in the field. But thats just me.