Honestly I thought all of the replies were going to be something like "1 tailed Naruto destroys" or something of that nature xd
Really I think it's at least a bit closer than what people are making it out to be. We don't have many ways to compare things like their speed directly but I guess we can make a general assumption. IIRC Naruto's lung got pierced and yet he healed a hole in his body. So if Naruto is serious about using the Kyuubi's power, Kakashi would have to aim for something like the heart (which Sasuke did but Naruto stopped him).