Haha!
I sent them an email at may or june, and they didn't answer yet
However I don't think these pipes are really bad if they are the 99% copies of the Yasunis. If they use the same sheet metal type and thickness the pipes are the same. Sure they use the common welding technique not the plasma welding, but this doesn't matter a lot!!
I don't know why are you so skeptical, why do you think if these pipes are much more cehaper they are even much more worse. You guys like buying the most expensive parts cause this is the trend
Sure you can watch the big brands name on your parts, but is it worth while?