Upconverted DVD Vs Blu-Ray - Difference On Screen Size

[Merc1785]

At what screen size do you guys think one begins to see a major difference in Picture Quality between an upconverted DVD and a Blu-Ray?

Of course, like Blu-Ray transfers, not all DVDs are created equally and some DVDs such as the digitally remastered Ultimate Edition James Bond or Superbit movies look "HD Quality" like upscaled.

I have a 32" LCD TV and some times I have a hard time telling the difference between the two. However, when I watch them on my 60", it is clearly apparent Blu-ray is superior.

I think it is a big advertisting point for us to prove to the uneducated consumer there is a major difference between upconverted SD and BD. Pushing HD audio of course helps too.