Can confirm the Helios are quite good. Using them off the Burson Audio Conductor 3X Reference in low gain. The bass quality is very good. I’ve actually been swapping between the MEST MK II & 64 Audio U6t for my commutes in the last two weeks and the Helios might be the front runner between the three. I’ve only had them for two hours of listening now though so take early impressions with a grain of salt but early on these feel like a real serious contender in the $1099 price bracket.
Shell size as well as nozzle are quite big though so for those with with smaller ears / ear holes, you may have some fit issues. The 2-pin connector portion also sits quite high which isn’t an issue with the stock 2.5mm cable but when using 3rd-party cables with memory wire hooks, it can sit rather high. This leads to the cable fit being loose instead of snug around the ears.
Despite those nitpicks though, the Helios is very impressive and I’m looking to spending more time with them this week!
Some of the tracks used for testing