Alan: I agree. Native resolution should be the target for your setup!
Unfortunately, that is not always possible. For example, my SXRD has its "native resolution" as 1080P. To the best of my knowledge none of the SXRD's inputs will accept anything "higher" than 1080I. There have been some reports that the PC input will take 1080P, but that remains an issue.
My Sony has a banner on the top that indicates what the cable content is broadcasting. In my Comcast case, it varies from channel to channel. It could be 1080I or 720P for HD and then 480 for SD. All of the signals, HD or SD, are "converted" by the Sony to 1080P.
The HD channels, no matter whether they are 1080I or 720P, all have the WOW factor.
I get the ABC, CBS, NBC and FOX channels both in SD and HD. Whether they are broadcasting in HD or not, all of them look better on the HD channel, rather than the SD channel. That may have something to do with the SD channels being analog and the HD channels being digital, I am just not sure yet.
For what it is worth, just a few observations thus far with HDTV.
