"Retina" is dependent on distance. Hold the 216 PPI about 3" further away, and it's as "retina" as the 264 PPI screen.
Yep, a very large screen, or high PPI, is good for that.
However, I use 7" tablets all the time for surfing (they're easier to hold in one hand), and I just tap zoom and the text reflows (on Android) so I don't have to scroll horizontally like on Safari.
I can't think of many times that I would have to type while web surfing.
So for an iPad 2 is "Retina" when I use it at 10 feet
The smaller the device, the closer you hold it, naturally. The only way to make sure you can't see pixels is to see the device in person.