GNC Pro Performance is a cheap set of nutritional supplements for a serious athlete. If you look at the nutritional information sheets, these products are exactly the same as name-brand products but cost much cheaper. Even without the cheap $15 GNC GoldCard, which gives you 20% off purchases, it's less than a dollar per scoop! Considering the amount of protein, fats, and carbs in this thing, it's a whole lot better than a burger from McDonald's dollar menu!
The difference between this product and its whey counterparts is that soy is a purely plant-based product so it's great for vegan bodybuilders or those who want more leeway in terms of fats in their diet. If you use the Soy Protein version instead of the Whey Protein, you'll be able to eat a little more fat in other meals. Soy Protein 95 has only 2% fat and 0% saturated fat!
As for protein breakdown, it's on par with everything else and includes the much-coveted BCAA amino acids that are vital for new weightlifters.
The only complaint I've heard from others who've tried this product is the lack of flavor. I don't mind the flavor myself. Just keep it mind that this isn't supposed to be a meal replacement or real food - it's a supplement! - so don't think the chocolate flavor is going to taste like SlimFast or Powerbars.