I like how when people figured they couldn't call Naruto stronger than Sasuke anymore (As they are equals) they had to swap out Naruto with another Uzumaki. (Just shows how blind the hatred is.) Now let me get to the other point.
Current Sasuke is better than Nagato. For several reasons really.
1. Madara's Rinnegan Power
Madara's power with the Rinnegan surpasses Nagato's in every way, he has already shown that. Sasuke was trolling Madara and surprised Madara several times, Madara even admitted that he couldn't take neither Sasuke or Naruto lightly anymore. (Madara didn't even say that about Gai, Obito or current Hashirama.) That alone is a testament, not only to Sasuke's power but to Naruto's as well.
2. Naruto is stronger.
Naruto is stronger than Nagato, that was prior to him obtaining any Bijuu cloak or chakra which he got during the war. Current Naruto is a lot stronger than Nagato, Sasuke is equal to Naruto in every way. Thus current Sasuke is stronger than Nagato in every way. Also, its clear that Sasuke's "Rinnegan" is different and Madara has been the only one to call it a Rinnegan, he may in fact be wrong about that as he doesn't even know about Indra's chakra that used to be inside of him.