Not a pro, but experience:
- Truthear Hexa: likely one of best price to quality ratios. Very neutral sound and good, only big issue for me is that I've managed to semi break 2 pairs of them. For some reason the other side just gets lower volume overtime. Not sure is it moisture or is it just shit getting stuck in or something.
- Truthear Zero Red: overall good and affordable. Slightly worse than Hexa, but your ear gets used to them so fast that they don't sound much worse. Bit more bass and muddy sound, but still good.
- Simgot EM6L(tested short time): very good and detailed sound, but they have this slight sharp sound to them that makes my head and ears hurt a bit. Definitely best audio out of ones I've tried, but I could see them being pretty unusable for some.
- Simgot EW300(tested short time): overall good, maybe slightly more bass than EM6L so slightly less details.
Overall I don't think there's big difference between them. Your ears get used to any of them fast and even switching between them isn't mind blowing. Truthear Zero Red by far the cheapest(like 50$), EM6L by far the most expensive(like 120$?). I would say out of these I would go with Hexa or EW300.Truthear default cable is shit though so I would buy aftermarket ones.