[Galaxy S 5 General] BarryH_GEG:
I realized after I posted that I've actually just gone through something similar. I was one of the first to buy the N10.1-14 in October of last year. You'd think with 2014 in its name it would stay fresh for a while. Samsung announced the Pro-line of tablets in January, two months later with 4.4 and features the N10.1-14 didn't have. Like some in this thread, I wasn't thrilled. It turns out it's a good thing the N10.1-14 isn't a "Pro." Magazine UX consumes a ton of resources and half the features shown at its unveiling at CES were neutered when it became official. It also doesn't support Samsung Hub. Now that the N10.1-14's on 4.4 it's actually faster and cleaner than the Pro's (M-UX has to have at least one home page).

A QHD display on a mobile device is ridiculous. The lowest common denominator isn't PPI; it's what the human eye is capable of resolving. QHD mobile devices and 4K TV's are pretty comical based on the distances they are typically viewed at. But to sell "new" higher margin TVs and get people to continue buying high-end mobile devices both are going to be drummed in to our heads as "have to have" by those with gazillion dollar marketing budgets that want us to buy them.

This explains visual acuity and is from a display test of the iP4 when it was introduced...

“Retina Display” is a great marketing name, and it’s the sharpest smartphone display available, 23 percent sharper than the nearest competitor, but objectively it does not meet the quantitative criteria for being a true Retina Display – it’s about a factor of two lower than the acuity of the human Retina. Rather, the iPhone 4 has a “20/20 Vision Display” because

when it is held more than 10.5 inches away, a person with 20/20 Vision will not be able to resolve the iPhone 4 screen pixels

, which are at 326 ppi (1 arc-minute resolution). But 20/20 Vision is the legal definition of “Normal Vision,” which is at the lower end of true normal vision. There are in fact lots of people with much better than 20/20 Vision, and for most people visual acuity is limited by blurring from the lens in the eye. The best human vision is about 20/10 Vision, twice as good as 20/20 Vision, and that is what corresponds to the acuity of the Retina. So to be a “True Retina Display” a screen needs about 652 ppi at 10.5 inches, or 572 ppi at 12 inches. Unfortunately, a “20/20 Vision Display” doesn’t sound anywhere near as enticing as a “Retina Display” so marketing and science don’t see eye-to-eye on this…​

But the above only matters when viewing certain types of content. This was from a discussion of 720P vs. 1080P displays...

Photos are inherently fuzzy, so it won’t matter whether they’re viewed on a 1920×1080 or 1280×720 smartphone display; you’ll still see their imperfections. "Even the tiniest image detail in a photograph is always spread over more than one pixel," Dr. Soneira explained in a follow-up e-mail. "The image detail is never perfectly aligned with the pixel structure of the display." Videos are even worse: not only are they fuzzy like photographs, but the pictures are constantly moving. Even if the images were sharp, the human brain couldn’t zero in on content that’s appearing for only a fraction of a second on such a small display. "For ordinary viewing of videos, 1920×1080 is really not going to make a visual difference," adds Dr. Soneira.

Where a 1080p smartphone display could really make an impact is with computer-generated content—that is, the user interface, buttons, and text.

"Only computer-generated images make full use of the pixel resolution of the display," says Dr. Soneira. "For graphics and text, maybe you want that kind of sharpness." Like desktop computers, smartphone displays can also utilize sub-pixel rendering, which helps improve the visual sharpness of computer-generated graphics.

A 1080p display might also be useful for simply viewing 1920×1080 content and not worrying about scaling. "

Every time you rescale content that’s scaled for some other resolution, it’s not going to look as good.

So there’s an advantage to living with 1920×1080 even if your eye can’t appreciate the fine details, because you don’t have the rescaling artifacts," he says.​

If the SGS5 "Plus" ends up QHD/S-805 I'd be willing to bet anyone here the current SGS5 will outperform it. I know this because the 2,560x1,600 display on my N10.1-14 causes it to run a lot slower than equivalent N3's using the same processor. More PPI (essentially doubled in this case) will consume more battery and any benefit of the improved GPU will be consumed (and maybe then some) by the display's enormous PPI.

The grass isn't always greener. I know because I'm in marketing and get paid a lot of money to make y'all think it is. ;)

P.S. - With high-end smartphone sales slowing down Samsung's looking for opportunities to raise their margins. If you think $50-100 is ridiculous for a storage bump that costs Samsung $10 I think you'll be shocked by the price differential for the SGS5+. All just my guess/opinion of course. ;)