I don't know if I'm just picky or what, but the line bleed on this set is bothering me. I've had a few times during normal content where it has been blatantly visible. Once during Futurama where it made if seem as if a character was transparent (face in front of wall with a line on the sides, resulted in a darkened area through the face that made it seem like the character was transparent) and then a few times during a normal live action show where in a certain area characters had dark lines on their necks. Definitely the screen, too, as I flipped the content back over to the laptop and it was fine there.
Also, I've noticed gradients tend to look very blocky and artifacty? It's really, really bad on any content that's remotely compressed. Even really well encoded 10GB+ 1080p BluRay rips are showing it on any sort of gradient. I understand these exist within the content (at least to a degree), but it's far more noticeable on this set than any other I've used. It's extremely bad on more compressed content (Netflix, TV rips, etc.) which make up the majority of the content I view.
I want to love this set (mostly since it's 65" and would be a pain to return), but these problems are bothering me. There's the buzzing too, but given that I had multiple UT50s do the same, I guess it's just how Panasonic's newer plasmas are. Damn, sometimes I wish I were more like the average viewer and could watch 480p 4:3 content stretched across a crappy screen and not even know the difference.