I'm inclined to side with your takeaway from this specific example. I don't see an appreciable difference, even on a MBPr.

I'd ship either, and if a designer told me he needed a extra time(and money) to ship the "better" product, and delivered me *that* -- I'd be extremely disappointed.

No doubt, designers pick at these things in their own circles, but outside of that clique, the business won't loose anything by shipping the "lower quality" product, sans the cost of design.

Indeed, there are parallels of this behavior in development -- people who are anal about cross-browser degradation or tedious about coupling/concern in code design. The process of graphic development for electronic displays should be one of building and agile response -- perfectionists exit stage left.

Individuals who think they are doing products a service with this level of detail are simply practitioners of academic pedantry, looking to stick feathers into their cap by reducing the amount of time it takes to edit everything into their respective resolutions; or simply bragging that they even managed to do it. A UX lab wouldn't even bother testing the difference.

Anytime an industry does a hand-wavy "It's just magic" or "indescribable feeling" bullshit, it's just marketing. I would be shocked if there was a statistically mesurable difference in the two designs. Personally, I haven't met any really amazing designers who focus on these kinds of detail. I meet plenty who puff up about these things by try and deflect attention from their mediocre illustration talent or inability to work in traditional media.

Don't worry, you're not crazy, just outspoken by a social clique of professionals with inflated ego.