The biggest flaw i can see with the MVP system is that certain roles will just get ignored. I suspect that Tanks will receive a high percentage of the MVPs for doing simple things like marking mobs. What can someone in a DPS role offer to set them apart from the other DPS in the party? What about players that perform their jobs perfectly but don't say a word while running the dungeon? I think the intent of the feature is admirable but it will be nearly impossible to implement in a way that is fair to everyone in the group.

This wouldn't be a huge issue if the reward was just bonus gil or tokens, but it has been stated that these will be unique rewards that are only available via this system.