It’s strange how all their models are so similar yet the He400i 2020 clearly stands out as the greatest headphone they ever produced. The other pairs all have at least one annoying thing about 'em… He4xx sounds stellar but can dismember on your head anytime, He400se has distracting upper mids shoutiness, Deva has kitschy “luxury” colors and lethargic mids, Hex4 and He5xx are the former headphones but with worse headbands.