I own the full size Storm 9mm, "C" Type. Am extremely happy with it. As far as purchasing the 9mm or 40.cal, its your choice. With all of the different trigger action options with the Storm 9mm, I am very happy with the constant action model. Extremely simple to quickly operate when time to multi-think is limited. No external safeties, simply point and shoot. ( And yes multi-think is a word ) at least in my dictionary. LOL. Enjoy whatever you purchase.