I know it'll be annoying to reply to both of them for a while, but please voice your comments on how they compare. I am looking forward to disable one of them ─ they're as annoying to me as they are to you

Well, to be frank, I disabled reCaptcha for posts but kept both for registrations. But some other pages may still show both.
I personally find hCaptcha more annoying, but some prefer it saying it respects user privacy more ─ I disagree btw.
So yes, feel free to comment what you think, if we should go back to reCaptcha only, or keep hCaptcha.