OK; opposite side of the coin here. I have the pink lemonade and can't live without them. In my opinion, Crystal Light leaves sort of an aftertaste, too. If I'm going to be drinking something (other than pop or coffee, which I can't have), I may as well get the Protein at the same time. After my first one, I didn't think that there was any noticable aftertaste to the K2O.
Good luck.