To paraphrase Tony Siragusa's answer of who the toughest OL was (I met him at one of Bruce's celebrity golf tournaments):
"Getting knocked on your a$$ is no big deal, it happens to all of us, but so-and-so (I've since forgotten the guy's name) with the Steelers had the sharpest fingernails I've ever seen. My arms would be scratched up and bleeding after every game - I hated lining up over him, he wasn't great, but toward the end of a game, I just didn't want to line up over him, I wanted no part of him - and that's the difference between a good lineman and a punishing one - you just don't want to lineup against him."