Well, i finally tried to make my own test. It would be easier to do if there were test patterns available on the various channels. With the picture constantly changing, by the time you change the settings and switch back and forth, it is really not a very good way to test.
First of all, I got rid of the RGB connection I has used since the beginning, and now use component inputs. I had even pd. for a top of the line cord. Using generic compnent def. provides a better overall picture by a very noticeable degree.
In looking at PBS demo feeds, both on the east and west feeds, the 1080i setting seemed better to me. OTH, on CBS, the 720p setting on the sat. recvr. seemed better. I'll do a further test on ABC and NBC. As mentioned, this is very subjective.
...mike
P.S. Just "tested" NBC. Didn't notice much difference between the 1080i setting and 720p setting, altho i would give a slight edge to the 720p setting. Again, i think the only way of really doing a test like this is with a static image, if not a test pattern.