We also know 23 million pixels for the whole system. So, 11.5 million for one display. a 4K display is 8.2 million. So it's not a whole lot more than 4K, and lower than their own 5K display (which has 14 million), which matches what they claim ("more than a 4K display"). That's not enough to cover the full field of human vision and still have pixels so small they can't be seen.
With corner waste it's just barely enough for one 4K display this way (and stretched to the full limits of vision it will be pretty unwatchable so close). You can't display two as you mention, because AR/VR projection works by using the 2 screens to display the same content just from a slightly different position (parallax) causing the 3D effect. The more overlap between the eyes the better and more comfortable the 3D effect (some headsets try to get an ultrawide FoV this way but shoot themselves in the foot with low overlap).
If it has a really wide FoV its sharpness will be pretty much on-par with a quest 3/Pico 4, if it's got the same FoV it will be a lot sharper. I expect the truth to be somewhere in between. Wider than a Quest and also sharper, but pixels visible if you look well and not quite full human FoV.
Still very impressive (which it must be at that price point obviously!). But real-world and not magic. Makes sense because Apple's engineers, as good as they are, are bound by the same laws of physics we all are. Their marketeers would love us to believe otherwise though.
It's really time for some real-world specs on this thing instead of marketing blah.
The exception to this is at the edges of your vision, where each eye does see a unique portion of the field, but by definition that’s not where you’re looking.
This is impossible at the resolution stated. The headset would have to be 8K or more per eye in order to achieve this, which it most definitely is not.
meaning a couple 4k screens can be rendered in the visible area without a noticeable difference in quality to real screens at a similar "apparent" distance