The comparison was imperfect, but not irrelevant. I followed up with Matt Williamson of Scouts Inc. for his thoughts:
Physically, they do have a lot in common. Roethlisberger is as physically impressive as any quarterback in the league today and there isn't a QB who relies more on his natural gifts than Newton. Both are tall, well built and strong -- and they play strong. Newton's movement skills are more sudden than Roethlisberger's, for sure. He runs with a better burst, is more elusive as a runner and probably runs with more power. But Roethlisberger is superior at feeling the rush and buying time in the pocket with his feet. While all those movement aspects of these players is great, the fact is that Ben was a far more refined passer coming out of Miami than Newton is today -- and passing makes the NFL go 'round.
Roethlisberger had much more passing experience coming out of college. He attempted 495 passes in his final season at Miami of Ohio. Newton attempted 280 at Auburn this past season. They both completed better than 66 percent. Newton averaged 10.2 yards per attempt, a very high number, and he threw a touchdown pass once every 9.3 attempts. Roethlisberger averaged 9.1 yards per attempt with one scoring pass every 13.4 attempts.
College passing stats often defy across-the-board comparisons. Both players were highly productive.