I just got around to installing Beta 4, and to say I'm unimpressed would be a massive understatement. About all I've seen so far is the Passwords app (big whoop dee doo) and the dictionary app bizarrely having a new "bookish" font, I haven't really noticed much difference. I know we get the mirroring app for iPhone but: a) not going to install beta on my iPhone; b) not really a feature I'll use in practice. I know we're getting some AI stuff but that all comes much much later.