Stepped or not stepped is a matter of the build components. As far as who did it first I think that Cycle Shack and HD did it long before anyone else, so if your worried about who copied who, better look to those that did it first. Better yet, look to see who is building them right as that should really be at the top of your list for it to work right in your application.
And there in lies the problem, Steve. Every manufacturer is going to tell you that they make their's right, otherwise they wouldn't sell. For the average motorcyclist that isn't a total gear head, we don't know which one is the "right one". So without spending a lot of money to test out all the different pipes out there, or going with the recommendations of the dealer, or independent tuner/builder, who's is the best for what application? I can go to different dealers or tuners and I will get a different answer. Some say, Vance and Hines, others will say S&S, but invariably, they all go with the major manufacturers that they are familiar with. Unfortunately, Fulsac, which isn't up in the "big leagues" yet, doesn't have the exposure, except in here, that the big manufacturers do. I have the X pipe on my SESG and love it, but yet my dealer/dyno tech, questioned why I bought it over the V&H Power Duals, because they didn't know about Fulsac and had never seen their product. So I guess my point is, it's all subjective. You will, and should, claim that you have the right combination/build. If you don't, you're out of business. No slight to anyone, that's just doing business, but determining the who builds the right product for which application, is difficult at best. You pick a product based on others, who have no vested interest, recommendations, and hope it's the best for your situation. JMO...