I have a furry and a hellfire. As far as volume goes the hellfire is a little louder. Both are the same with clarity, good. The firestorm will give you two speakers to wich allow you to adjust between the two to sound like a wounded animal is turning its head. The hellfire is way better for crow hunting. I would say that if you are going to be calling specific directions and locations predator hunting then the hellfire would be your better choice for the added benefit of being better for crows as well. If you are going to be predator hunting spots wear your not exactly sure wear they are located then the firestorm might be your better option. Since the firestorm has two speakers it will allow you to be able to call from two direction 180 degrees apart, but the hellfire will give you a better single direction calling ability. When I crow hunt I only use the main horn speaker on my furry so the hellfire has been bringing the crows in from mush farther away for me. I just face the speaker strait up.
Either call will work great for you and your needs, they both have there advantages. Good luck with your purchase and hunting!