I just wanted to thank everyone on this thread for great comments and advice. It made my decision to buy this TV much easier. I already have a Roku device for internet streaming and don't have any interest in 3D, so getting the best TV picture for my money at less than $1,000 was my goal. This forum made the decision a no-brainer.
For those looking for another great deal on these TVs, try your local Sears store. Costco was out of them, so I went to Sears and they have them on sale for $699 through June 15, 2012. AND, if you have a Sears charge card, you get either 18 months to pay or another 10 percent ($70) off. I chose the latter and got the TV for $629, plus tax. Took it home in my SUV so no shipping charge either. And the picture, after following the recommended calibration settings, is sweet.
BTW, I know the focus here is on picture quality, but another factor for me is product quality and reliability. Consumer Reports shows that Panasonic TVs have the best QC in terms of repairs and serious problems reported at 3 percent for Plasma TVs. LG is at 8 percent and Samsung is at 5 percent. Just another reason to like the Panasonics.