IMO, the situation dictates on how you run or how you pass. Both can be effective given the right situation.
If the other team does not stop the run, stay with it. It eats up the clock and demoralizes the opposing team. But, being able to exploit the other team by passing can also demoralize the opposing team...so, what do you do?
You play the "chess match game"...take what you can get because one over the other is not a good way to try and win a game. The league is a passing game prevalent now days, but that does not mean that the running game does not count because it does. If the Cowboys could run like they did this last game, I would stick with it all season long and just let the QB throw his passes when he sees fit...just take what you can, one way or the other, and you will be successful.