I'm not sure I'd go so far as to say that. Obviously, Fullsac considers the stepped pipe to be important or they wouldn't go to the trouble of building it that way. But, I'm not sure how much difference you'd feel between the two when riding the bike. I'd bet that most people wouldn't be able to tell any real difference in the real world. I take most Dyno charts with a grain of salt, other than just a general indication of what's going on. BTW, I have the Fullsac pipe, but don't see anything inherently wrong with the other product, or the way it performs. They're both close enough for guvment work...
Yes TC, that is what I said. Fullsac has a tuned pipe, just like BUB. They spent the time to do the work necessary to put out a quality product backed by years of research. The MotoJunk pipe is, "Just Pipe", no engineering or thought just a cheap copy of the better engineered FullSac pipe, kind of like a cheap chinese knockoff!
The seat-of-your-pants-dyno will also know the difference. So TC, since I don't work for the guverment, I will accept the dyno chart as proof the MotoChinaJunkPipe is not as well built.