When people say "Base person A" or "base person B," you're just stripping away a person's weapons or techniques just to make them match up to whoever you're trying to make look better. To say "sasuke without his sharingan" is a senseless thing to say because sasuke will not be without his sharingan. You create an unrealistic battle situation that would never occur. If sasuke enters a fighting tournament, they will not make him remove his eyes for the sake of having an "even fight." Obviously, fights aren't even, and thus have a winner. The same is true of naruto: you can't say "oh, but naruto without his kyubi is not as good as sasuke" because the fox is a part of naruto the same way sasuke's eyes are a part of him. The same could be said of kakashi and his sharingan, itachi and his sword and mirror, kisame and his sword, or any shinobi with a summon. Its a senseless argument
On the other hand, I don't believe that naruto 300 trillion times less powerful than sasuke without using any kyubi powers. Naruto was able to take 5 of pains paths without using the fox (and actually defeated the final path without the kurama). This was not a situation where naruto had some sort of "type advantage," but a true display of naruto's abilities in head to head combat against an enemy who outnumbered him greatly. Considering nagato's skill level high enough to be considered the leader of the akatsuki for a time, i think it is foolish, biased, and inaccurate to say that Naruto's skill is so far behind sasuke's. pain defeated two sannin (each of which was powerful enough to be a kage) and great number of jounin (including kakashi, who is also considered to be on kage level). Despite this, naruto was able to defeat him (with some enemy intel help). I feel that without the kurama, yes, naruto would lose to sasuke in about 80/100 fights, but lets be smart about what we say, regardless of our particular affinity to any 1 character (sasuke fanboys)...
On the other hand, with all of his current fox powers, naruto would likely beat sasuke in 65/100 fights... that will likely change as sasuke develops his ems and naruto's bond strengthens with kurama.