Most MRPs contain varying amounts of whey(concentrate, isolate, and/or hydrolyzed), albumin, casein, and/or soy. Most of the one's put out by the big companies, including those you mentioned, are of good quality. The biggest variations are usually in AMOUNTS of protein, carbs, and fat grams...as well as in taste and texture.
There are a handful of companies that put out "all whey" versions, however.