I think the best way to put this is: can Clayborn potentially be just as much of a game-changer this year as Suh was last year? I do think so (though I am a little biased). BUT Clayborn plays defensive end. It's easier to dominate a game from the DE spot than it is for a DT like Suh. So Clayborn could have just as big of an impact, but he's not as good as Suh because he's at a position that makes his will easier to impose. Fair enough?
But there have been a few DT's that I've seen in my life who were at least close to as good as Suh. Warren Sapp (in his prime) comes to mind. He wasn't the same style of DT, but he was arguably just as dominant. We may never see a DT like Suh again (meaning as lean, athletic, etc.), but that doesn't mean we won't see one better. He's just so different from the norm when you picture defensive tackles.