I would feel more comfortable directing you to the AVS Forum web site. They have specific threads for these two models. Do your search and ask questions there. They are more into video and have some excellent technical resources and contributors. Make sure you check out the calibration thread for whichever model you decide upon. It really makes a difference to use proper settings.
http://www.avsforum.com/avs-vb/showthread.php?t=1324116&highlight=samsung+pn64d7000
http://www.avsforum.com/avs-vb/showthread.php?t=1331665&highlight=panasonic+tc+p65vt30
http://www.avsforum.com/avs-vb/showthread.php?t=1324116&highlight=samsung+pn64d7000
http://www.avsforum.com/avs-vb/showthread.php?t=1331665&highlight=panasonic+tc+p65vt30