I've tried the optimum blend in both vanilla and chocolate along with the hydrolyzed WPI in vanilla. The optimum is a good choice to go with mainly because the price is great. The optimum, for me at least, didn't like to mix but it wasn't anything a little extra shaking couldn't handle. The taste was excellent. I can't say the same for the hydrolyzed WPI though. It mixed quite well but the taste was pretty rough, to the point of not wanting to drink it at all. I've also had a sample of the Rejuvenix in the orange flavor from a buddy of mine and I would consider the purchase of a bottle of that on my next order. They have a good thing going on at AllTheWhey so it's most likely a safe bet with anything that you're looking to order. They're good people and their orders ship to me in around 2 days.