I'm not even going to say anything. I'm just going to hope you all have ESPN Insider. If not, I feel sad for you. There might be a free version later. If so, I'll link to it.
Compared to his regular-season numbers, Roethlisberger's performance in the playoffs isn't good. It's right in line with Tom Brady and Brett Favre, each of whom see their performance drop in one category or another. Manning actually retains more of his regular-season performance during the playoffs than any of the three, while -- incredibly -- Kurt Warner actually put up better numbers in the playoffs than he did during the regular season! Part of that is because most of Warner's playoff experience came as part of the "Greatest Show on Turf" St. Louis Rams teams at the beginning of the 21st century, but Warner is criminally underrated as far as late-game heroics go. He threw a game-winning touchdown pass to Isaac Bruce on the only play of his final drive in Super Bowl XXXIV, produced a game-tying touchdown on his final drive in Super Bowl XXXVI, and then threw a touchdown pass to Larry Fitzgerald to take the lead with 2:37 left in Super Bowl XLIII. (His final drive started on his own 11-yard line with 30 seconds to go.) He was let down by his defense in both of those losses.
It's a pay only article, so I won't link more. Just know that it exists, and it's wonderful to behold.