Keep in mind that there is no standard for "Hi-Gluten" when it comes to flour. We have tested some HG flours and found them at between 10 and 11% protein content, while others are at 12 to as high as 14%, especially for the commercial flours such as All Trumps, Remarkable, Big Spring, Power, Regal, Gigantic, Hi-Rise, and Dominator, to name just a few. I agree with Norma, and I'll go so far as to say that regardless of what it says on the bag, if the flour works for you, it's the right flour for you. By all means shop around and evaluate different flours, experimenting is half of the fun of making pizza, the other half is eating your creations, and as I've been known to say, "don't worry about making mistakes, they'll taste good too".
Tom Lehmann/The Dough Doctor