He's still one of the strongest Naruto characters, the only thing is that it would cost him his life. If he opened all 8 gates, he could go head to head with Naruto and Sasuke easy, maybe even beat them. (We don't know for sure, since we've never seen it, but if it's more powerful than 7, and it costs your life, chances are it's fairly strong).
Plus Naruto isn't just about how (physically) hard, how fast, or how precise your hit is. It has a lot to do with the energy (chakra) behind it. Show has always been this way.