Beef protein is all marketing hype - it offers no advantages compared to the ordinary whey protein, none at all. However, due to this markenting hype they charge quite more for this protein, so I would rather go with a very good classic whey protein. The best one you can get, should be 100% whey isolate - in such case the results should be great. Personally, I use the Isolation of N2BM, and it is an awesome protein product - 100% isolate, no artificial sweetners or additives, it has a very competitive price, and the taste is plain awesome. My favorite flavor is the Colombian Espresso - tastes like a very good coffee coctail.