Yes, at double the pixel res (quadruple the pixels) of the old iPad, [full retina res] graphics look better — in my opinion maybe 5-10% better. Is that enough to justify slower performance and twice the wait to download the app? In most cases, probably not. Apps that are very text-heavy get a better boost, certainly, than graphics. And for show-stopper games that are essentially art demos, like Infinity Blade II, I could see justifying it. As a pure marketing strategy it could also make sense.
When iPhone 4 hit, I asked my wife’s dad, who is a retired retina surgeon, about the new display. He thought it looked awesome, but also thought the retina claims were oversimplified, pushing the truth and part marketing/hype.
Do most apps really need the extra resolution and sharpness? Raymond Soneira says probably not.