I think it comes down to who runs out of chakra first, Susano'o drains chakra much faster than Minato's FTG and, quite frankly, he doesn't need it against Sasuke. DUE to the simple fact that Sasuke did not appear at all faster than the Raikage, and Minato's foot speed and reaction time was faster than A's. Sasuke also feels pain while he maintains Susano'o. So I don't see Minato using FTG until he needs it. If Tobi didn't hurt Minato, I can't see Sasuke doing it at this point, EMS or not. Of course, he will definitely surpass Minato in the long run.