You notice pixel density between 400 and 450, or 450 and 500 when holding the phone normally (at say a bit less than an arm's length usually)

I mean, I notice FPS changes from 60 to 90, but I wouldn't pay even a dollar extra for it.

I'm not actually wondering if you can notice, I'm wondering if it makes an actual impact on your viewing experience.

And if so, if that impact (however big or small, feel free to elaborate) is worth the extra money we can all assume it costs to buy hardware capable of pushing a lot of extra pixels smoothly.

And lastly, if that different not only is worth the price, but also the hit to battery life we can all assume exists.

That, to me, just seems like a really tall order. (if anyone has some insights as to how big the impact is on viewing experience, cost and battery, feel free to add! I've got no real clue).