For me, it's because Grow! is the only protein that actually tastes good to me, other than chocolate muscle milk.
Spike is the only stimulant that I have ever felt "worked".
ZMA is about the cheapest supplement of that type on the market, and it works well too.
The Metabolic Drive bars are like candy and don't have any soy protein in them.
Carbolin 19 is the god damn shit!