I walked into Best Buy today after a few days research sold on the Panasonic tcp42u2. I was convinced for the best picture quality we needed a 1080p plasma. However, after both my wife saw it in person we reconsidered. It seemed the 1080p plasmas all had very blurry pictures. The 720p plasmas also had blurry pictures, but not as bad as the 1080p. My wife also complained the picture looked blurry on the 240 Hz LED, and 120 Hz LCD. In the past the split screen comparison, the 120 Hz looked sharper. So we went to Wendy's for lunch and discussed it.
It occurred to me, virtually all raw video source is 30 Hz. If you are watching video on a 600 Hz plasma, software will need to extrapolate to generate the in between frames. That will make the picture more blurry, but it will also make motion, action, and sports smoother. The cost of a smoother motion is a blurry picture. In the past the split screen comparisons I saw with 120 Hz and 60 Hz LCD was very little motion, just a slow panning. So my past observation was consistent with the hypothesis.
After lunch we went to Costco. Sure enough, that is exactly what we observed. 60Hz LCD's look crystal sharp, but motion looks jumpy... Now since all the video source used to demo at Costco as 720P, we could not fairly compare the 720P to the 1080P. However, our observations at Best Buy lead us to conclude upping the resolution required even more software extrapolations, making the picture even blurrier. Since virtually all our video source is 480P or 720P, we decided we the only difference we would ever see between the two is the additional extrapolation blur in the higher resolution TV. Neither of us have good enough eyes to see 720P pixels from the couch, so we decided on the tc-42px24 from Costco.