Like pretty much everybody else, I can appreciate the jump from 720p to 1080p. 1080p obcviously being better. I just don't see as big of a jump from upscaled to 1080p vs native 1080p. I've purchased three different HDTVs (ending with an LED early last year) since 2007 in search of the perfect picture and I tweak my console settings and TV settings until I think I have the best possible pic--even when I don't know what some of the settings mean!
In the end, the difference just isn't that prominant to my old man eyes. I do only play on 42 inch screens, though. Maybe the difference is better on bigger TVs. I don't know.