Unless you have problems with lactose, or are on poverty macros where even 1g of Carb or Fat matter, go with an 80% Whey Protein Concentrate. The only thing Isolates get you is less cals/carbs/fat... some also say WPC is better due to intact micro-fractions, etc... And like above, there is some good data showing that combining it with Miceller Casein is a good idea.