Two chidori is Sasuke's limit for the day, which he's not supposed to go over.
He didn't go over it, and he barely took any damage compared to the fight with Gaara, in which..
1-He'd fought with Gaara in the chuunin exam, using chidori once, and a semi-chidori to get his hand out of the "ball," as well as all the Rock-lee style taijutsu
2-He'd used bunshin, kawarimi, explosion notes, Katon(fire) style ninpou versus Temari
3-He'd used chidori again versus Gaara, and AGAIN versus Gaara, which went over his limit, and made him collapse, as well as blocking Naruto from slamming into a tree.
I'd have to say that compared to the "damage" Aoi gave him, which was a slice from an energy sword that "Can cut through ANYTHING.. except Human flesh and clothes, apparently!," two chidori, and he has to be carted out on a stretcher?
I wouldn' say that's quite even, even if he had done some running earlier, as well as being hit by the needles/lame energy thing, and fighting with the hidden rain ninjas way earlier.