I'm using a subkey now. There's no UX to it. But its a much better experience for me than an old account. I personally dont really need a follow list of likes etc. to enjoy nostr. What I think would be good is if I write a profile app that allows an extra field in the profile that lets you add an array of subkeys.
How the UX will evolve after that, I dont know. But I'm hooked on subkeys, I dont think I'll go back.