I just last week upgraded a Philips 50" to the Panasonic 50" PX6U.
Picture quality of the Panny is noticeably better than the Philips (especially the day I hooked up the Panny after having the Philips for less than a month before it totally died! UGH!)
I don't currently have HD/Digital cable (boo Comcast), but the DVD picture is nice.
1: CRT has a better picture quality for both SD and HD!
2: If at all possible, buy your Plasma TV or LCD TV at Costco! 100% customer satisfaction survey that never expires! If you are no longer satisfied with your TV, even in five years, or especially if something ever, ever, ever goes wrong, just take it back with the receipt and get a full refund!!!! No questions asked. This is why they don't even bother to offer extended warranties at Costco.
No, I don't work for Costco.