Plasma displays don't use artificially inflated refresh rates like LCD must to prevent ghosting. The phosphor decay rate on a plasma display is tuned to be right around 1/60th to 1/72nd of a second. Just in time to be energized for the next frame.

Pioneer PDP-5020FD, Marantz SR6011
Axiom M5HP, VP160HP, QS8
Sony PS4, surround backs
-Chris