And what if you could tell the difference?
Well it gets tricky. Can I tell the difference in the store, side-by-side? Will I actually know the difference when it's at home in my living room and I have not against which to compare? If I actually could see the difference during normal use at home (ie the viewing distance was too close) then it changes the calculus, and I'd have to decide what was more important to me, resolution or the aesthetic. I'm a hi-fi kinda guy (fidelity has to be good enough, no tv speakers for me), so it would be a serious consideration, sure.
You've said you can tell the difference on the moto x, and the reviews seem to confirm as much. Given that you haven't used the phone as a daily driver I'm still skeptical that you or the reviewers would be pining for more PPI without something side-by-side to compare to, but that's just a guess.
The fact remains that moto maker is a big reason this phone is the same price as the other flagships. Without manufactur in the US customized phones would take 4-6 weeks to deliver (by boat) or be $100 more (via air freight). It is my suspicion that the hardware in the phone is on the order of ~$10-20 cheaper on the BOM (I did a quick and dirty analysis on this previously), while the US manufacturing at least makes up the difference, hence the retail price. That aesthetic is important to some people, and not important to others. For those of us who value the customization, it's no skin of our back to "give up" the extra hardware specs, the argument being that we'd never notice much of a benefit from the extra specs to begin with.
What I'm still confused about is why I haven't seen any moto X commercials. With a $500MM budget I expect to see ads on my fucking toilet paper, yet I've seen almost nothing. Maybe they'll launch this thursday during the NFL season opener. Either way, I find the story compelling, and I suspect a lot of other "normal" people will too, but that's just my opinion.