In truth, Plasma's had better PQ as recently as 2008. This year Samsung and Panasonic LCD's seem to have gone to the next level. Surprising that an older Panny Plasma would be so notisably better than a recent Samsung LCD.
I suspect you would get more bang out of it if you calibrated it.
What model Samsung did you purchase?
I bet its very thin. At CES the 2009's looked ridiculously thin!
check out how thin