I'm currently using your Strength and Power 6 Day Advanced workout. I obtained some GNC whey protein for free and I was wondering what your opinion on this product is. Also, all the instructions on protein drinks recommend mixing with water, I was wondering if mixing with skim milk has any effect on absorption or anything highspeed like that.
Also, I've mixed some Instant Breakfast in it too for flavor and Vitamins. Does this have any negative impact on the protein?

The GNC Whey protein powder is fine. Whey protein is great to take in directly after a workout because it is absorbed so quickly. You can definitely mix it with Skim Milk or an instant breakfast packer for extra flavor, protein and vitamins. Most of the people I know who use Whey protein do the exact same thing!