I have also noticed that the HDGuru's "best" designation changes frequently. However in his defense I must point out that the state of the art in video reproduction does advance incrementally and he does a good job of keeping abreast of the changes. It is also true that the HDGuru, or any other A/V web site or printed A/V publication, had best frequently say good things about a product they are loaned for test purposes, or the loans soon stop happening.
But I also have a bit of a conceptual issue with medium-sized plasma displays such as the current test of the TC-P54V10. For my purposes and my tastes, medium plasma displays have little real purpose.
There really are two applications for video displays. One is a home theater application where you seek the "total immersion" experience where the display subtends a large angle of your vision. The optimal viewing distance for this 54" plasma display, based upon the HDGuru's seating chart, and the viewing guidelines from the SMPTE and THX are between 5 and 8 feet (approximately, the reccomendations are similar but not identical). At that rather close viewing distance, you could fit two people on a couch. Any more seats, and you have excessive geometric distortion from the viewing angles. Ideally, the two seats would be in the center of a surround sound "sweet spot". The room should ideally be in near total darkness to avoid distractions.
The second purpose of a video display is the simple, all-to-common occupation called "watching TV". This is a lesser level of interaction with the video and actually is but a part-time occupation, you can read or converse or nibble or even work. The basic parameter of "watching TV" is that you be further away and that the screen occupy a lesser area in your total view. This is a distinctly and different experience from the total immersion of a theater experience (commercial or home theater).
The "watching TV" experience requires a display with a native refresh rate compatible with 30Hz and 60Hz video materials. The only plasma technology that offers this capability is the (out of production) Pioneer Kuros with user-selectable 60Hz/72Hz refresh, and also 120Hz/240Hz LCD displays. Within these two choices there is room for a preference for LCD or Plasma. However the Panasonic HDTV model TC-P54V10 is a singularly POOR choice for "watching TV", it's fixed 72Hz refresh will compromise motion smoothness with video material that originates as 30Hz frame rates (1080i60) and 60Hz frame rates (720p60). As a Home Theater display, the TC-P54V10 is not a bad choice for up to two people on a couch, and provided all you want it for is watching 24Hz video sources. But the TC-P54V10 HDTV is a poor TV display.