Your eyes must be shot as I can tell the difference between 720 and 1080p at 14'. I tested out many TV's when I replaced my 55" RPTV and I could pick out the differences. Things like grass on a field. it's not that you can see specific detail, just you see that something is just not right if you put them both up side by side.
That said, i would not buy a new TV just for the sake of it. If your current one works for you then i would just keep on using it.
Nope, I've got 20/20 vision. Well, with my glasses on.
We may well have different levels of accuity. I'm going by the chart I linked to. I seem to fall within its working premise as I was barely able to tell the difference between 1080p and up-scaled DVD at 8' from my 50" rptv. They are night and day different on a 110" screen at 10'.
