As a 16x9 owner who communicates with many others through the net, I think I can safely generalize in saying we don't use our sets for NTSC or VHS sources. Watching Katie on a 30" DirectView is one thing, on a 56" screen - don't go there.
Most RPTV's today have all kinds of "Stretch" modes so that you can fill the screen with NTSC image material. Forget VHS entirely - 480 lines interlaced(240 lines rastered every 1/60 sec.) doesn't cut it, stick with DVD - 480 lines progressive(480 lines rastered every 1/60 sec.) is acceptable for a widescreen.
What these sets are made for is HDTV. At 8ft away from a 56" screen, the 1080 interlaced line pictures are gorgeous. Soprano's look twice as threatening in 16x9 format.
All RPTV's can display NTSC, SDTV and HDTV. The SONY "enhanced" I believe is called DRC, where they take formats that are generating less than 1080i and scale those lower resolutions up to 960i. This is reported to give a better looking picture than the original source resolution one.
To see what some low resolution capture images of HDTV on a Widescreen set check:
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