I'm currently selecting an RPTV and am a bit confused with the upconversion feature. "NTSC-to-480p progressive-scan upconversion system improves picture quality with conventional sources." Does this mean that I don't need a progressive scan DVD player? I get the impression that the upconversion feature basically does the same thing a progressive scan DVD player does. If someone could give me more information about progressive scan upconversion I'd greatly appreciate it. Thanks.