You have to love em and hate em.
For the position of quarterback — arguably the most important, difficult and glamorous position among the four major American team sports — the prime age is so large it fits in a skyscraper-sized window.
Because the best quarterbacks often are the most physically gifted, arm strength is never better than when a quarterback is in his mid-20s. But because the position is more about smarts, study habits and making instant decisions than it is arm strength, the prime adjusts with each new year of wisdom.
Dan Marino was 23 and in his second season when he went to his only Super Bowl and threw for a still-standing NFL-record 5,084 yards. Ben Roethlisberger won two Super Bowls by the time he was 25, but his maturity seemingly regressed at 27. - Link
Rather than Advanced Stats I used available stats :)
These are the cumulative Passer Index ratings from www.pro-football-reference.com by age:
100 is average, higher is better
|Player||Age 25||Age 26||Age 27||Age 28||Age 29|
Make of it what you wish.