This is a tough call.
The obvious downsides are timeshares and inconsistency.
I think you start Bradshaw, because he can put up a lot of yards on a few touches, and even though Jacobs "started" last week, Bradshaw surprisingly got some goal line work, along with his sprinkle of regular touches. You also have a much more serious clock risk with Peyton Manning under center against the Cowboys. There's every reason to think that the Colts will have greater time of possession and will be in the lead for most of the game, which reduces run time. On the flip side, the Giants SHOULD beat Washington, Washington SHOULDN'T dominate time of possession, etc, and playing from a lead usually means more touches for any RB. Playing from a big lead usually means the #2 RB gets more work in the second half as well. You can make a good argument for starting Felix. I'd start Bradshaw.
Give me your thoughts on mine?