FWIW, as is the norm, my experience is that it works brilliantly --as long as you stay within apple defaults.
As soon as I stray from golden path - text using anything but Apple MEssages, email using anything but apple mail, post using anything but safari, use/process with anything but Apple Photos - HEIC has been an absolute positive pain in my keister ;-(
Other people may have more luck; note that my work iPhone is an isolated island - my other devices are either Android, or Windows/Linux - which probably explains my troubles to a large degree. Apple's selling point has always been the well-integrated ecosystem so I understand I'm an outlier.
Which is why IOS should default to sending JPG or PNG to/between any non-bespoke Apple product until such a time that HEIC is universally common. That should be transparent to both the end-user as well as the receiving end.
One can moan about the test site not being more robust/careful but it is Apple/Samsung that are using the new, non-standard format and expecting others to accomodate in short order.
As soon as I stray from golden path - text using anything but Apple MEssages, email using anything but apple mail, post using anything but safari, use/process with anything but Apple Photos - HEIC has been an absolute positive pain in my keister ;-(
Other people may have more luck; note that my work iPhone is an isolated island - my other devices are either Android, or Windows/Linux - which probably explains my troubles to a large degree. Apple's selling point has always been the well-integrated ecosystem so I understand I'm an outlier.