[SimpleMinds]

I think that's the W1 chip reference - when you have multiple devices signed to one iCloud (mac, iphone, ipad?) you pair with one of them once, then for other devices they are "just there", in list of available devices. You don't need to separately pair with each one. Tiny but useful. Other than that they are normal BT headphones (I believe)

[MrQuincle]

Yes, for Apple Homekit for example the long term keys for bonding are stored online, so this means you can access from a different device without the authentication process.

For headphones it doesn't make much of a difference. However, if you're manufacturing more devices that all needs to be setup and shared with multiple people it's a pity that the key deployment is Apple-only. That is, I don't know of an official way to get to the keys to get a seamless experience across vendors.