I can't see comparing Roth-less-burger to Trent Dilweed. That dude sucked. Big Ben is legit. He didn't have the poor pass protection the first 2 years of his career. They babied him along. Now that the pass blocking isn't so great, he has not reacted well to the pressure. He needs to learn to throw the ball away. And quick.
Big Ben was a young QB, who's job was to not lose the game. His stat lines bear this out, and the Steelers won in much the same fashion as the Dilfer-led Ravens. He hasn't shown himself to be in the same league as Manning, Brady, Brees, or even Delhomme.
Agreed Big Ben is not in the upper tier of QBs yet, but he ain't bottom of the barrel as Dilweed was much of his career.