Bobby, I think we're gonna have to agree to disagree on some of this in terms of actual vs percieved value. I do see value to IMAX Digital where I don't see the same value to "premium large format" digital (especially if that doesn't include Atmos), and to my eyes, it genuinely does look better. While IMAX may not have the monopoly on dual-projection, in practice in my area they essentially do. The ETX and RPX theaters near me all operate with a single 4K projector, not dual projection. Perhaps if I had a non-IMAX dual-projector digital 3D system to observe, they might get my money over IMAX. I'd certainly try it, but as far as I know, there's nothing like that around me.
I'd agree with you that none of these formats (besides real film IMAX) are truly "large format". No argument here. The only point I was trying to make is that at least IMAX Digital offers something, that specific work is done in remastering the images to the screens. I think of that as being similar to blowing up 35mm to 70mm as used to happen - doesn't make the film itself magically large format as if it had originated on 70mm, but it does yield a better result than a 35mm print. To me, the other brands of "premium large format digital" aren't like 70mm prints of 35mm films -- they're like 35mm prints being shown on a 70mm sized screen.
If all IMAX's DMR process does is hide the pixel grid for the large screen presentations, I still say that's something. There's apparent sharpness in the image without an apparent screen door effect or other pixelization that I see present in non-IMAX 2K and 4K digital presentations from time to time. Frankly, I think IMAX is designed for people who love being super-close to the screen, and I'm definitely one of them. Their thing is all about having the screen overwhelm all of your other senses, and everything from the size of the screen, to its placement, to the location and angle and closeness of the seats, is about that. Even in a properly configured digital IMAX auditorium, you're still getting some of the advantages like the closer seats and the floor-to-ceiling screen design that make it appear larger than it is. I've found that aspect lacking in the imitation IMAX rooms -- the Regal near me advertises that their RPX screen is 20% bigger than their regular screens, but the seating distance and viewing angles are similarly scaled, so that it never achieves the "in your face" effect that I get out of an IMAX movie. (This is probably as good of a time as any to mention that I was definitely "that kid" that sat too close to the TV screen and was constantly being warned I was going to fall in! Umm, that was the point!)
Bobby, I do particularly appreciate your writing on the different sound technologies and speaker placements, I'm less up to date on that stuff, mostly for the reasons mentioned in my previous post -- that my ears don't hear all that much of a difference, especially with where I choose to sit. Still, even if I haven't really noticed the benefit of it myself, I'm eager to know what's out there and being used currently. As I mentioned, Atmos has done nothing for me the times I've seen films in an Atmos-equipped theater (the films I saw in that format were G.I. Joe Retaliation, Star Trek Into Darkness, The Wolverine, and Thor: The Dark World - someone on the Atmos thread posted that none of those movies were noted for having impressive Atmos mixes in the first place). I'll check out the Auro 11.1 format if it's offered near me.
I wish IMAX wasn't mothballing all of their projectors and abandoning what made their format great. They really need to do something about how they're presenting digital features on their existing 15/70 screens - the digital presentation IMAX does in a room designed for digital is fine, but at least at the Lincoln Square NYC IMAX, it's painfully obvious that the digital projection system doesn't work well in that room. The projector cannot fill either the width or height of the screen (I'd expect at least the width!), and having a severely windowboxed image sitting center of a massive screen is less than ideal. Unfortunately, that still ends up being a bigger image than at any other theater around here, so I find myself going to those presentations anyway. Supposedly that location is getting a laser projector in December (after "Interstellar" finishes its run), and supposedly that laser projector will be able to fill the entire screen instead of a postage-stamp-sized square in the middle, so here's hoping that that turns out to be the case.
Would that I could, I'd watch nothing but IMAX 15/70 prints, 70mm prints of large format films, and 35mm for everything else. (And perhaps when I get my time machine, I'll do just that!)