I bought the same tv around the same time, and have the same issue as you. It is not as good as my old plasma(600u) model bought in 2006. the only differences with the new tv is smart tv but think it is not worth it this time.
I am still trying to change some settings and see if it works better.
I recently purchased a Panasonic TC-P60VT60, based on the reviews here on cnet.com. I have an older Panasonic plasma, model TC-P50G10, which I still have, I just moved it to a different room. My issue is that I cannot get the new plasma to equal the picture quality of my older plasma, and according to the cnet reviews, this new VT60 is supposed to be one of the best out there.
I've tried several different HDMI cables, and I've followed the calibration settings on cnet.com, that were used in their review.
My main issue is that I cannot seem to get a "clear" picture on my new plasma, it's no where near as "clear" as my older plasma. Does anyone have any ideas for me, or any changes I can make in the settings? I do have the new plasma in a dark or dimly lit room, and I've adjusted the settings per the cnet review, and I've gone through other settings and changed them as well, but I'm not able to get the picture to look near as "clear" as my older plasma. This new VT60 almost gives me (and others) a headache while watching it - so please let me know if anyone out there as any comments or ideas for me, thank you, as I'm about ready to take this TV back to Best Buy if I still can