I would bet that if you end up in a tie situation for a room upgrade, the PPs (providing the property knows what that means) would win out. Other than than, no real value to PP. There have been some reports where the FDC tried to explain that Platinum was higher that Platinum Premier.

Given PP is believed to be a % of membership, the only goal you can shoot for is to spend more in dollars and nights than 97% of the members... As soon as one goes $0.01 above you, your status may drop.