They sound good (above average), and the cashew shape fit my ear nicely.
However, here’s the build quality problems that plagued mine:
1. Right out of the box I heard something physically rattling around loose in the left side. There was zero bass on that side too. I opened it up and found the dynamic driver was not even glued in place - it was just loosely flopping around inside the shell. Once I glued the driver in place, it sounded normal including bass.
2. The cable is a 2-pin, but not like KZ/TRN. I think it’s a common plug that was developed by Audio Technica, but don’t quote me on that. The shape is trapezoid; similar to a mini-USB (the larger precursor to the micro-USB). Anyways, both of mine were very loose and it would cause annoying random sound cutouts. I smooshed and deformed the trapezoid-shaped male 2-pin plug with pliers, which allowed it to fit tightly and solve the cutout problems. In their defense, I believe this was not an unheard of complaint even with genuine Audio Technica IEM. I guess it’s just a crappy design, which could explain why hardly any company uses that style of plug. Again, I could be wrong though.
3. My right shell fell apart on the 2nd day, with only about 4 hours of total listening time. I was able to glue the 2 halves back together.
Vidal (the now defunct Aproear) also had similar problems with his. I know for a fact his shell fell apart. I am not sure if he had other QC issues though.
I think
@HungryPanda has a pair. Again, not sure if he had problems with his.
In any event, as much as some people pick in KZ, their build quality and QC reliability is 10xs better than MDK-ESS (at least the few models that came out at the end of 2017 ie ASK etc).
Hopefully they’ve made a conscious effort to improve the build quality. It at least appears that way with this new model.