It adds to the immersion, of course - I am not going to dispute that. My point is that at this stage I don‘t like the proposed trade-off: increase the FoV to the max at the cost of higher resolution per degree. If we had i) the displays (16K) to give us retina resolution over >200 degrees and ii) the GPUs to power that, I would be a happy bunny.
But we don‘t have neither of the two. Not even close. And at this stage I prefer focusing the resources (resolution, GPU capacity) where I get the most out of them. Which for me is the center 150 degrees. I hardly notice it when I switch to large on my 8KX so I usually don‘t make use of those 20 extra degrees. And honestly, on 70% of the games I don‘t really miss the Pimax FoV so much when using the G2.
In terms of picture quality, the 12K will offer approx. 28 PPD while the Aero e.g. already offers 35. But that is only half of the story: the Aero needs 7.8 mln. pixels to be rendered while the 12K needs 15.3 mln., almost twice as many pixels. So expect to drastically reduce many ingame settings for this kind of usage.
Bottomline for me is that the additional 50 degrees over the 8KX the 12K would be providing cannot get me excited. Not as long as my GPU to drive the beast will only be a 4090, 5090 or 6090.
You could say the 12K will be ahead of its time. Problem is, by the time the GPUs have caught up, I expect vastly superior headsets to be available.