Truth hurts.
No one made a hollow tube and bent it. MD actually designed something close to a dozen designs with different bends, resonator designs, glass packs, etc. before finally settling on the best and selling that. That's precisely what engineering is. There was R&D here. Test pipes have virtually no R&D.
I had HFCs. I had test pipes. I had ART Pipes. So coming from someone that owned all three, I can easily say the MD product is simply superior in every possible way, in sound, design, and power. I don't mean to come off like an *** about it or anything, I'm simply saying. It's been dyno proven, as well.
People selling their cars need not apply to this convo.