Getting an exp boost while leveling is technically an advantage, it's not one that is usually considered P2W. You cannot win at leveling in most games. Even if you reach max level first it rarely means anything or anything worth any importance.
But if you can buy flash point and operation gear at max level with real cash and not actually playing the game - Thats considered P2W and looked down on by a great many gamers.
It's even a little more broad if you start taking PVP into account as well.