Hi E.S.
What are you watching that is in native 720p format? I am assuming you are talking HDTV. Most broadcasts are 1080i with FOX, ABC and ESPNHD being the only ones that I know of in native 720p format. If you are talking those channels I can agree there may be a difference but it would hardly be noticeable at all on the other channles on 2 perfectly calibrated TV's.
What HD do I watch? Uh, I dunno, the typical stuff I guess...I get these channels in my HD package:
ABC, NBC, CBS, FOX, PBS, CW, TNT, ESPN, Discovery Theater, INHD, HDNet
As for the difference that I see between 720p and 1080i, perhaps it would help if you understood the two
very different types of sets I was comparing. The 1080i was a *TUBE* television, which as you know is natively an interlaced device. No matter what you feed it, everything it displayed was interlaced.
Now the 720p set is a DLP, a natively progressive-scan device. If you give it a 720p feed, it displays a progressive-scan 1280x720 image. But if you give it a 1080i feed, it deinterlaces it and downsamples it to (ta-da!) 1280x720 progressive scan.
If you don't believe me that there is a massive difference between the two, you're more than welcome to come over to my house; both sets are still in my living room sitting side-by-side, and the difference is staggering.
Plus, it'd be a helluva good excuse to smoke some kickass cigars. :smokingbo