Thanks for the info on the dual inputs on the 720. I guess I must tell the HDTV receiver what my display resolution is? Or do I just let them figure it out for themselves?
I'm not a DTV expert, but I do digital video production.
NTSC is based on B&W TV, with color added after the fact.
The FCC mandated "backward compatability" so the color is actually modulated under the B&W signal and this extra information is what slowed it down from B&W true 30 fps (interlaced) to 29.97. In analogue RF (cable or broadcast) you got a carrier, video signal stereo audio signal (and whatever interference, multipath etc) all taking up 6 Mhz os bandwith and multiplexed together.
The DTV signal offers true component color video, separate from audio, from the outset. Now the bandwith of a DTV signal is the same as that allocated for NTSC broadcasts (which is how they can coexist on the air and on a cable) but the information for audio (even 5.1) is compressed and packetized separately so the two don't interfere. This is what led to audio sync issues in the early receivers. So, with true component color, delivered at various frame rates and sizes (NTSC or better) in a way that you see exactly what what was compressed, you can understand how good DTV is.
For a wacky (but incredibly informed) view on DTV, its promises perils, I recommend Mark Shubin's columns in various trade pubs. He's discarded more information than much of us will ever know. His latest is here:http://www.digitaltelevision.com/200..._schubin.shtml