Well this basiclly been answered from their battle at the valley of the end.
Naruto(with no mode) was tanking sasuke with a partial curse mark lv 1.
Then Naruto was fighting even with sasuke with a two tomed sharingan.
Then Naruto(with fox aura) owned sasuke with a two tomed sharingan, but then sasuke turned the tables on with a three tomed sharingan.
Then Naruto( in one tail mode) owed sasuke in 3 tome sharingan then sasuke needed to go curse lv 2 mode to cause a stalemate.
Not mention sasukevon the hospital roof felt very inferior to naruto after their clash with no modes. This is why he left konoha by the way in the end.
So I think Naruto natually is stronger than sasuke. Sasuke is naturally faster than naruto. But the decider is the fact that naruto naturally has a lot more stamina than sasuke. Also naruto doing a bigger rasengan would own chodori. Not to meantion if naruto did a small wind rasengan. If sasuke had stronger fire jutsu things could have been different, but he focused on lighning.
And saying naruto cant use summons is silly, its is a jutsu really. Is it naruto's fault that he has more chakra than sasuke? Same with sage mode, it is something he learned like summoning.