When people talk about Jackson's shortcomings they point to his pedestrian 21:18 touchdown to interception ratio and his 10-9 record as a starter.
What people seem to neglect is that he is long past that point is his career, and 2008 was a year in which he turned the corner and really started to come into his own.
In 2006, his rookie season, he was 0-2 in two starts and threw 2 touchdowns to 4 interceptions in the 4 games he played that season. When he took the reins, the Vikings were 6-8, and had already checked out for the season.
In 2007, he began to progress, but couldn't shake the interceptions that haunted him in his rookie season. He was 8-4 as a starter, and in the 4 games he didn't play the Vikings were 0-4. He had a 9:12 TD to interception ratio, and ran for 260 yards.
Finally in 2008 Jackson started to become the quarterback the Vikings expected him to be when they traded up to get him.
After being benched for losing in weeks one and two to very good Packer and Colt teams, he came back in week 14 and in 3 subsequent starts tore through opposing defenses and posted a rating of well over 100 over the last three games of the regular season.
This year was a major step forward for Jackson and he posted a QB rating of 95.4, had a very respectable 9:3 TD-int ratio, and rushed for 145 yards on only 26 attempts.
Last year, under Favre, Jackson looked phenomenal in his relief appearances, which were quite frequent considering the Vikings successes.
He threw for one touchdown, no interceptions, and posted a rating of 113.4 over six appearances.
Although these came against downtrodden teams in the fourth quarter, a 113 rating over 21 attempts is nothing to sneeze at.
To recap: Since 2008, Jackson, in the action he's seen, has been superb. He's thrown 10 touchdowns to 3 interceptions, and has looked like everything anyone would want in a starting QB.
His early career struggles are what he is being judged by as a player, and no one seems willing to acknowledge his consistent progress from year to year.