I'm late to this thread, but I see that the OP is heading in the direction that I would also recommend - ie. larger screen size and plasma
For certain I would recommend a larger screen size than 55" from 12' away. If you were to follow the SMPTE recommendation of a 30 degree field of view, from 12', SMPTE would recommend a 88.5" 16:9 screen, which, of course, would only be available with a rear projection or front projection setup (or an insanely expensive flat panel
)
The minimum recommended screen size - which would fill a 24 degree field of view - from 12' away is 70". So even aiming for the minimum, it's tough to find an affordable flat panel at that size. But there are 64" and 65" plasma options as well as 70" LCD options from Sharp and 65" LCD options from Samsung.
It's just something to keep in mind, but basically, with a 12' viewing distance, you should aim for as large a screen as you can manage!
What bothers me the most about all of the large LCD options is that they all have extremely glossy screens. There are no matte screen options, which I think is stupid. Some people don't mind the mirror-like screen surfaces, but they bug the hell out of me! With ANY light in the room, I can plainly see my own reflection staring back at me whenever the scene on screen is dark or has black images. I HATE seeing reflections of myself or the room or light sources, so the super-glossy screens are a total deal breaker for me.
The other trouble spots with most LCDs are uneven screen illumination and off-angle viewing. With edge-lit displays, the lighting behind the screen is not uniform and even. You get some spots that are brighter and some spots that are dimmer, leading to a "cloudy" look on dark scenes. And if you're sitting over to the side, colors shift and dim and the black level often rises or becomes uneven across the screen. Both of these issues are completely eliminated with a good plasma, which has virtually perfectly even screen illumination and off-angle viewing.
With all of that said, I still favor Panasonic's plasmas myself. I've noted on some of the new Samsung plasmas that they still develop some "phosphor lag" - sometimes right out of the box, sometimes after several hundred hours of use. Basically, if you suddenly go from a bright scene to an all black scene, you sometimes get a tiny "ghost" image that lingers for just a moment. I haven't seen that same problem on the newest Panasonic plasmas.
Where the Samsung plasmas really shine is in the lower priced models where Samsung offers far more picture adjustment controls and better color accuracy. Other than the top-of-the-line VT30 models, Panasonic really skimps on the user control options. They certainly aren't bad in terms of color accuracy, but the lower priced Panny's aren't perfect, and you have no means to adjust them so that they are perfect. Your only option is to call in a professional calibrator, or get some professional level calibration equipment and break into the service menu and calibrator's menu yourself
Anywho, at the end of the day, I'd get a 65" Panasonic plasma if I were in your situation. The ST30 line is a great choice for lower price, excellent picture quality and the option to use 3D in the future if you want to. I don't have any big problem with getting a Samsung plasma. You can probably do so for a lower price and you will get that more accurate color and more user adjustments. But that "phosphor lag" really bugs me personally, and the Panny's still have a tiny edge in black level performance.
Good luck in your decision!
