There's no question about who I'm taking if I'm offered the choice of both players in their prime. I've said it before, I'll put Revis 2009 season up against any single season performance by anyone doing anything football related in the history of the game. It's the cornerbacks equivalent to Brady's 07, Dickerson's 1984 season, etc.
Sherman's aged far more gracefully and had WAY better of a "second act" in his career so to speak, and its not even close. I don't think I've ever seen someone as legendary hit the wall that young or fast as Darelle did.