I know that the magnitude of a revamp like this would be massive, but I'd play an updated XI over XIV anyday.
IMO, the gameplay elements that make up XI is the best MMO setting ever, but I feel estranged after being spoiled by next generation graphics and faster gameplay.
That being said, I don't want XIV to be XI-2, I would rather it be it's spiritual successor and start to become more unique after the ground work has been laid out.