Ironically even Crinacle himself has pointed out that distortion is lesser relevant in IEM design, however this was years back, to what degree he thinks so still today idk. I do think that the distortion from BA's are what people people consider part of the "Plastic/BA timbre" Its definitively audible thought there are features like out of head staging/imaging which I would say are quite noticeable in higher end IEMs. There's also potential that 64Audio's in house response is relative to some in ear HRTF curves, which are measurements that Harman's published research didn't deal with.I performed AB tests between the two and did not at all detect such a difference. What I heard was that the Zero sounded so much better without EQ. And was more resolving, cleaner to boot. The zero has much lower distortion which may explain, together with proper balance, why it sounds better.