Hmm, I'm not an expert, but I thought if you upconvert from one resolution to another you simply add stuff that wasn't there in the first place. It might match better the resolution of your display, but it doesn't necessarily mean it will look "better". If DVD 480P is upconverted, or rather "stuff" is added to the image, I would think there is a very good chance at 1080i/720p the image could look better than at 1080p where you'd need to add more of the extra "stuff". Again, I'm not an expert, and good chance is this would differ on different equipment, but this is what my "common" sense is telling me.