Yes, there is a difference on the quality and quantity of the Whey. Most people agress that the Optimum Whey soy is good enough but there are better ones. However you have to take into account the price. Optimum Whey is made out of Concentrate while others are made from Whey Isolate (which I have red nobody does because the Stuff tastes so bad nobody would take it, so they add more stuff to it make it digestable or at least not to taste that bad). There are differences on the Whey Protein as there is on the Juices. There is a difference on an Orange Juice made from Concentrate, from one made from real Oranges but it is going to be more expensive. There are several brands that are pretty good in selling high quality Whey but it costs like $65 for 6 pounds. EAS is supposed to be a little better than Optimum. Also, the Optimum has more fat thatn the EAS. Inregard to proteins I take a Shake with one Scoop of Whey protein and One Scoop of Soy Protein (tastes kind of bad by itself, plus with the Whey I make sure I am getting enough protein on my shakes plus is really inexpensive). Here is a small extract about the Diferences on the quality of Whey:
What is Whey Protein? Whey protein can be found in a variety of different protein shake blends. However, some proteins concentrate on 100% of ion exchange whey protein isolate. Whey protein concentrate provides shorter and longer chains of amino acids. Whey protein is ideal for lactose intolerance and anyone sensitive to milk products. Designer Whey and Isopure are two whey proteins examples. Extreme Pure Protein by Worldwide Sports Nutrition is also a whey protein drink that is also low carbohydrate and known throughout bodybuilding as being a whey protein zero carbohydrate drink. Whey Glutamine peptide blend containing a full spectrum whey peptide protein is found in new Designer Whey Protein by Next Nutrition. Whey protein shakes and whey protein drinks despite being a better protein source than egg white protein or soy protein is intended to be used as a food supplement, and is an excellent way of supplementing fat burning and protein requirements throughout the day.
Whey proteins shakes are available in a variety of flavors such as vanilla, strawberry, and chocolate. Whey protein drinks are also available in several flavors such as fruit punch, orange cream and grape. Bodybuilders and athletes find whey proteins are more compatible for their digestive systems as whey protein is lactose free, as well as being lower in calories, sugar and having low carbohydrates.
Whey protein can be found in a variety of other protein shake and protein drink blends. For instance, whey protein is also included in Pure Gro's blend of 5 different proteins including egg protein, milk protein, soy protein and calcium caseinate protein. You can also use whey protein in many of your favorite cooking and baking dishes to ensure that your body is getting sufficient daily intake.
I am going to add Calsium Caseinate Protein.