These IEMs sound awesome. Using them with an LG G6 (built-in amp), they have great detail in every aspect, a good soundstage and depth, and are very clear with separation of instruments. They don't have so much treble that there's sibilance. They don't have loud, fatiguing bass. They don't have a bump in the mids that veils everything else. They sound well balanced and detailed, exactly what I look for in IEMs.
MAIN ISSUE: DURABILITY
The huge issue with them is the durability of the cable, or perhaps just the jack on the cable. I had to contact Massdrop for a replacement after TWO WEEKS of using these, because any time the jack moved around the audio cut out in the left ear, until the audio was just gone completely. Now, I don't know how "badly" I treat my IEMs, but they are portable, so all I do is plug them into my phone, put my phone in my pocket, and walk around places. Or, I'm just using them at home sitting still. I only wrap them to put them in their case.
Yet, after another 4.5 months or so, the audio on one side started going out again. I feel like they should have more durability than that for their price and how well-constructed they look. I'm pretty sure it's just an issue around the jack, but still, why is it so hard for every company that makes IEMs to get that right. I haven't had a pair of IEMs last longer than 6 months, with the exception of some Soundmagic E10's I had years ago.
But if you're willing to pay $30-$100 for a replacement MMCX cable every 4 months or so, I'd try these out. I'm about to buy another cable for them just because they sound so good.