a little note, i see most of you think that naruto has the kyubi in his control alredy but i do not think that naruto will anytime soon have the "FULL" control over the kyubi. why do i think that? becose if you look on every single jutsu from naruto he eather didnt master it 100% as the original jutsu or he had limitations if he uses that jutsu let's take an sample
rasengan he has to use 1 shadow clones and him self to do it (the original just uses the 1 person)
futon rasen shuriken now he need's 2 shadow clones and him self to perform the jutsu, but also this jutsu has the downfall that it not only hurts the enemy it hurt's naruto too.
sage mode. he truly made it he is probably the best sage ever but again a limitation due to the inpossibility to merge with pa and ma he can't maintain the sage mode long ....
now why would the kyubi power come without any problems affter we waited years and years? what kishi will just make pufff to the kyubi and naruto has the control over it???
this training will take far longer then you think. and i doubt that naruto will have full control over the kyubi maybe big control but not full.