What difference does it make? If the ball was amazing people would still be criticising the players kicking at 100% and say it's a boring world cup which doesn't have any tries. The ball is the same in every game, the players who practice with it most on the training pitch, will be, and should be, the most successful with it. You can't expect reward for not doing something, or sit back and blame other things for your actions. The very few kickers who are doing well with this ball are obviously training harder, and as they say, it takes a while to get used to, so even more reason to spend more time practicing.
This world cup shouldn't be marred by allegations of a dodgy ball, everyone is on an even playing field, those who adapt quickest deserve their success. I would hope that no nation comes out post-world cup and blames their loss on their inability to kick the ball straight, it's no excuse.