Dropped by TW Trinoma yesterday with my family and had the chance to see the 50PV70 vs. 50PY70 side by side. On playback was "Disturbia" BD.
My immediate impressions on a 6ft viewing distance:
1. Color - 50PY70 stands out. You don't have to look longer. It's really obvious.
2. Resolution - Both have just the same look. You'd have to look closer and a little longer to see the better difference of the PY70.