Thanks, everyone! Had to skip a few to make the T20 #350, but it's an interesting IEM to be sure.
soundstige
's post is great - way more detailed than mine would have been. I don't have much to add except that I too would not recommend getting an Ety for under-helmet use - with the long housings and angled strain relief they're really not the ideal shape. in addition to what soundstige recommended, I think the Aurisonics Rockets, or even a Yamaha EPH-100, would be a better choice if cable-up/ergonomic earphones aren't your thing. These IEMs isolate very well (not Ety-level, but close) and they don't stick as far out of the ear if you wear them deep enough.
Great, another phone maker enters the fray