I enjoy looking at splits... I feel like they tell more of the story:
http://espn.go.com/n...15803/ej-manuel
He's only thrown 16 passes in the second half of games this season, compared to 31 in the first half. In the 4th quarter, he's thrown for 78% completion percentage... so being asked to not do much, but when he is called on, he's ready. On third downs he's passing for 62%, 9ypa, and almost averaging 5 ypc on keepers.
In the RZ, he's 3-6, two TDs.
To me, these things all speak towards someone who is improving and continuing to improve. These are clutch situations that he's performing in. Did he miss a couple passes that could have been TDs? Sure. Is he perfect? Nope.
He's 12 games in, and is showing improvement, pretty steadily.
Even if he stinks the place up this upcoming Sunday, to me, he's shown enough at this point to stick with developing him.