This was my 3rd pair of IEMs over $50, after the Thinksound TS-02 and the Sennheiser IE80. For me, these are my go-to beater earphones. However, they do have their flaws.
TL;DR - Minor build issues and relative in-efficiency compared to other IEMs mar an otherwise decent set of earphones. Still recommended though.
These are, to my ears on par with, or within striking distance of the IE80. The sound is decently fun, and detailed. These and the IE80s kind of pump sound into your head, giving you more of the feel that your head is the microphone than any ear or headphones I've listened to. Though, admittedly that is a small sample size. However, in the Virtual Barber Shop, when Luigi taps the binaural mic, it reverberates like he actually tapped my skull. Have driven these from a few different sources and they sound about as good as I can expect them to sound from a Shanling M0. Soundstage feels wide enough and imaging is alright. Of course, tips make a big difference, but with a decent seal, I get enough bass to be happy on the go.
Oh, the sorrow. Had mine about a year now, maybe more. Periods of both heavy and no usage, so probably 6 months of average usage. They're mostly in the case. I always wind the wire. I started to have problems with frequencies dropping out during listening... Like I'd lose all treble and mids would sound very far away and recessed, but bass was still present. I'm pretty sure it's the cable, but it's obnoxious. Also, like many others, the coating has chipped off near the seams, mostly. All that said, the MMCX connectors on the earphones are still working, and having dropped them a few times, there's no dents or damage aside from the coating. They're basically tanks. Sure, they're heavier than my IE80's by a wide margin, but...
These are some of the most comfortable universal fit IEMs I've ever had in my ears. Compared to the odd shape of the IE80's, these are like a pair of earphones actually designed for a human ear. It may very well just be my ears are pretty average, but damn. I used the foam tips for a while but they got wrekt pretty quick. I'm using the single flange large silicone tips right now, which seal well and have held up spectacularly so far. They stay in my ears well to be honest. The thick cable doesn't help with my glasses though. I usually end up wrapping them inside the wings to keep the wire in place and because it's thick(ish) and braided, it tends to hurt over long periods at work.
So, this deserves it's own section? Yeah. It does. These IEMs are 50 Ohm Impedence and 96dB sensitivity. Those are some full size headphone numbers. Specifically, those are T50RP Mark III numbers! They're dynamic though and not planars... Dunno how much that matters. But compared to the pretty efficient actual IEMs that are the IE80's, these things are monsters to drive. Though, to be fair, most phones will push them to reasonable volumes, and in my experience, the Shanling M0 was enough to push them to their max potential, as I heard no benefit from an FX Audio DAC-X6 with considerable more power, or SE through the Aune X7s. These ARE still IEMs, but damn if those numbers don't require a little extra power...
I think these are still good IEMs for the price. They're comfortable, sound decent, can be driven decently-spectacularly by portable gear. look classy and understated, use the extremely common MMCX connector making replacement cables easy to find, and they come with a variety of ear tips to suit most.
Their only real downsides are that the coating isn't very tough, and the stock wire doesn't seem very sturdy. Oh, and the efficiency could be annoying. Either way, I can still recommend them at this price, but with the minor build issues remedied they would easily be in my top 2 for an IEM between $50 and $150.