Got mine (50ST60) last week direct from Panasonic. Replacing a 50" Samsung DLP set (which I loved, but was starting to get the "white dot" problem and probably needs a bulb soon).
Compared to the DLP, the default color tones are pretty bad, everything has a greenish tint on the Standard mode. After calibrating it in Custom I'm a lot happier but still need some adjustment. The picture is a LOT sharper than the soft detail of the DLP, that takes some getting used to. I'm playing around with the motion smoothing, I prefer to keep the picture as close as possible to the source.
The picture is fairly dim and looks better in a darker environment, but it is neither too washed out nor too reflective in brighter light, it's still acceptable.
The DLNA feature is nice, but I miss the PS3's ability to search a video to a specific minute and start playback anywhere. But it does play MKV videos which the PS3 doesn't (ahoy maties, if you know what I mean, wink wink nod nod).
Can't comment on sound since I have it connected to a Yamaha RX-V473 receiver. I am having an odd problem in case anyone has suggestions: everytime I turn on the receiver and TV I can't get any sound out of the receiver at all until I turn it up to very high volume, but if I turn the receiver off and on again the volume goes back to normal. It doesn't happen if I just use the receiver by itself (with Airplay, etc.) so I'm assuming the problem is related to HDMI CEC/ARC between the TV and receiver.
Overall I am happy with the purchase. LCDs are BRIGHT but other than that I think Plasmas offer a better, more natural picture.