nick: I would strongly suggest that you go and spend some time watching some of the various HDTVs side by side. I don't think that the trades are 720 vs 1080 or plasma vs sxrd.
I think that you would be better served looking at the contrast ratio, how the color edges merge into one another, and how you like the over picture quality.
I don't think that plasma burn in is as much of a problem today, as it was a few years ago.
I have 2 Sony SXRDs. One is a 60" and the other is about 32." I am very pleased with both.
rat - nice job. My mantra is usually "trust your eyes/ears" to make the decision and I sometimes forget that advice.