No. I haven't. But I am not doubting their sonic capabilities. They might be fantastic sounding. But I have very little faith in that brand's QC in general. And that's why I'm averse to paying significant monies to them. I might be wrong but it's better to be safe then sorry
LOL, to better be safe than sorry you'd better buy everything locally with a warranty. I think I've got 6 IEM's from this brand (and the MT300 on the way) and haven't had any QC issues with either and I also think that they all sound from good to very good compared to other offerings at their respective price points. As always YMMV but I really think that your arguments here is more true to Chi-Fi in general than this specific brand. Especially since you don't have any experience with the items you're asking people to stay away from.....