My 3-month old Pioneer KRP-600M just answered all my similar questions about today's picture quality improvements in the affirmative. I researched the terrific new Panasonic V and X models just coming out as well as the new stunning LED LCD models.
I suspect I would be happy with any of today's new top of the line models; however, picture quality and consistently super low black levels outweighed that extra 5 inches for me.
I loved the picture quality of my finely tweaked 2003 Panasonic 42 inch 480p model so much more than any 720p or 1080p models that I saw in stores, I finally let the comments of the many AVSforum posters I have respected sway my final decision.
I am really happy that they did. Using DVE-HD Basics, I see that the grayscale, shadow detail and accurate color space is significantly improved over my old, but still gorgeous Panasonic. Being really anal, I did find a few areas that have been compromised for cost and efficiency. I recently posted my thoughts about the louder buzzing from the panel when I am very close to it. With the exception of a few moments on Bloomberg.com, I have never noticed it in normal usage.
Likewise, I almost hesitate to mention something I noticed relative to my old Panasonic glass front. The Panasonic glass does pick up reflections like a glass window, but it also has the same crystal clarity of a glass window. By contrast the new Pioneer 600M has an excellent anti-reflection coating which eliminates all reflections unless you are looking at it almost from the side angles. That or I suspect the plastic film filter on the back of the glass causes a very slight hazy glow around high contrast transistions such as the edge of bright white titles on a black background.
Most people would not notice this and I have finally resolved that it is an acceptable trade-off for what I perceive as much better contrast overall. I found a way to duplicate this affect on both my niw Pioneer and my old Panasonic. By shining a six-inch lon Mag-Lite flashlight into the the powered-off screen, I can see a diffusion of light about six inches in diameter on the Pioneer and two inches on the Panasonic.
The Pioneer wins on that point because the screen can still be black enough to still see that haze when it is on and has a video black signal applied. My old Panasonic which was once the ultimate in dark gray black levels is simply not black enough when on, to notice the two-inch haze. I never noticed it, in six years.
I really hoped this might be my year to go with the LED LCD but looking at them in showrooms convinced me that I personally prefer what to me are the sweeter, more effortlessly-natural looking picture of the Pioneer and nearly identical looking in the showrooms, Panasonics of 3 months ago when I made my decision.
I probably would have waited another year, but posts by people such as Tom Huffman, Turbe, D-Nice and other calibrators assured me the 500M was #1 in picture quality and almost visualy identical #2 was the 600M.
I crossed my fingers and bought the 600M. After three months, I am one happy camper even without the isf calibration which I will do in the not too distant future. Meanwhile I revel every day in the huge (IMHO) improvements in blacks, near-black shadow detail, colors and grayscale accuracy that were not possible to display on the old plasma set.
Last night, I watched the end of Ken Burns' "National Parks" documentary. In the final minutes there is a very black night scene looking down on Yosemite valley with a city-at-night-like display of firery bright lights from cars and campers. As I sat mesmerized by the still frame, analyzing the spectacularly contrasty scene without a hint of the haze I occasionally see on title scrolls, I suddenly noticed an ever so slight pattern of black-on-black ovals in the blackest unilluminated corner of a hill. I used the remote to crank up the black level to see if what I thought I was seeing was an anomaly or part of more black detail being crushed. It was neither. It was a slightly different level of black where no trees were growing amidst the nearly impossible to see black on black outlines of tall trees. I returned the black setting to my calibrated normal (-1). It was much better than any black-on-black detail I have ever seen anywhere.
This is a great time to upgrade.