Review on 🎧 FiiO UTWS3 Bluetooth V5.0 aptX/TWS + Earbuds Hook MMCX Connector with Mic Support - Enhancing the Listening Experience for Shure SE215 SE315 SE846 SE535 SE425/JVC/FiiO FD5 FH7 with 30 Hours Playback and APP Control by Heidi Davis

I've had it for a few weeks and am very happy so far. I had a TRN BT20s Pro before purchasing this model. Both are equally suited to a true wireless IEM, but FiiO's performance is superior in many ways. Here's how they compare: Sound: Perhaps one of the most important features when transitioning an IEM to true wireless. FiiO has raw power, but the clarity and extension of both high and low frequencies is better than TRN. The typical Bluetooth noise is also very quiet with both, but much less noticeable with the FiiO. Finally, the microphone quality on FiiO is significantly better than on TRN. Please note that no Bluetooth technology can beat a physical connection. With FiiO I mostly notice a lack of fine detail in the upper highs and a slightly compressed soundstage. Fit/Finish: The FiiO sits tighter on the back of my ears, but I find the hooks are a bit short and tend to hang over my ears rather than wrap around them. This is where TRN has a slight advantage in my opinion, but your experience may vary based on ear size and IEM. Features/Versatility: FiiO has a major advantage in that it has a companion app that lets you change button configuration, choose from preset equalizer settings, adjust volume, and is open to future firmware updates. FiiO also has a more powerful built-in amplifier that works well with less sensitive headphones. TRN misses a lot here, but has a killer feature: the hooks can detach from the battery. This means you can buy additional hooks with different connectors (MMCX, 2-pin, etc.) without having to buy the whole block or adapter. FiiO offers a 2-pin version, but it wasn't available on Revain at the time of writing this review. So you may need to consider buying MMCX to 2 pin adapters or resort to buying from another market. Carrying case: TRN and FiiO have taken very different paths here. TRN made a fabric-covered, zippered case. It's convenient to toss in a bag, but it doesn't exude quality. Inside the case there is a good pocket for storing accessories (which I miss when using FiiO). On the other hand, there is no battery level indicator on the TRN pouch, and the large earbuds have to be rotated to fully close the pouch (this can be cumbersome with a 2-pin IEM). FiiO has an anodized aluminum body that opens with a magnetic clasp. This is a good presentation, but the surface may scratch over time. The earplugs fit into a small rubberized pouch. Finally, a useful addition is the 3-light charge level indicator. My only complaint other than the lack of an accessory pocket is that the magnet used to align the hooks doesn't seem very strong. With TRN I felt like I could almost drop the hooks and they would snap, with FiiO it's like a conscious effort to make sure the hooks are seated and loaded. Both use USB-C charging ports and do not support Qi wireless charging. Incidentally, the FiiO app inspires me the most. This is clearly in its infancy, the Guide tab is still empty on iOS. But I have already seen the firmware update, so FiiO is clearly working on improvements. I hope to see custom button configurations, custom EQ settings, improved call clarity, and maybe even active noise-cancellation one day in the future. (Update): I liked them so much I got the 0.78mm version. Unfortunately, it has a serious design flaw. Instead of having rectangular pins, they protrude straight out of the round temples. It looks good but doesn't match the design of the 0.78mm cables. As a result, most 0.78 headphones don't sit fully and can easily fall off the hooks during handling. I'm deducting a star for this oversight.