I don't have Arias but I do have Moondrop Kato and Truthears. I don't find nozzle size a problem (I guess I have cavernous ears
). The Katos are a better fit while the Truthears are still OK but unsuitable for use within a helmet or while lying on side. But neither is 1st class ergonomic design. The Moondrop Chu is second class in ergonomics but still better than these premium IEMs. For me the best designs have been the Massdrop Plus (conformity to human anatomy so perfect it felt like custom made) and Vsonic GR07 (somewhat ergonomic shell + rotating nozzles meant a really amazingly good fit and unexpectedly effective isolation). For me none of the Moondrop IEMs (I have Quarks, Chu, Kato) nor the Truthears even approach the fundamentally sound ergonomics of the Shure SE series, which have been around *forever*. They do sound better but they are not so easy to wear, nor as sensitive. Mostly I'm now listening with the Truthears but if my Massdrop Plus hadn't failed I'd never have bought another IEM, or wanted one.