Boyd;
The "big" thing that All Trumps flour has going for it is that it is one of the highest protein flours commonly available. It's great for making any kind of pizza where a chewy crust texture is desired. It is not the only flour that will impart this characteristic, but since it is one of the highest protein flours, it is presumed to do this the best. In actuality, any flour with about 12% protein content, give or take 0.5%, will make great pizza.
Tom Lehmann/The Dough Doctor