Well, I don't think its about the wings, and you might be right. I'll rewatch the episodes and post some screenshots I guess. The thing with Gaara's defense is his damn sand. It seems like Chidori can only cut through the part its touching. I think when the sand was repairing itself it stopped around Sasuke's biceps/shoulder, stopping him from going all the way. However, Neji's Kaiten isnt that "strong" physically compared to Gaara's. Since its just a whirl of chakra, Chidori should be able to kind of slice it.

Are you talking about Naruto 4 for gamecube? Well I'm getting the game and it seems like a half decent player can own with lvl 2 sasuke, kind of like a cheap characters (from the videos I've seen). Also, if they made him really fast, neither the controller or opponent would know where he would show up.