On the evidence shown so far, Sasuke could NOT beat Naruto with the ems. As impressive as the Amaterasu frisbees are, Naruto's speed in bijuu mode is way too fast to catch with that. Also, just because his Susanoo has a cloak doesn't mean it's defense has increased massively. The differences between the various Susanoo's we've seen aren't a case of different levels, just aesthetic choices by Kishi. Itachi's had a cloak without the ems, and it looked most human too (We can assume Sasuke's is stronger at this point, apart from the legendary items Itachi has). Madara's was more monstrous, to match his personality. Sasuke's is dark, but not as inhuman looking as Madara's.
So at this point, it's foolish to state Sasuke is stronger than these other characters. There's no real evidence to support it. It's likely he will surpass Itachi and Madara, if only to keep his rivalry with Naruto interesting and live up to his role in ending the Uchiha/Senju rivalry