MW5 has a few scripted missions, but mostly to level through them you do non-objective/ non-goal based generated missions. Maybe 20 of those to 1 scripted story line mission. So, usually you are playing for no goal of any kind. And the repeat grind sets in fast.
But what if?.......
There was a MercNet Mission board that laid out certain completion rewards. Like a mech or Gauss Rifles. Maybe Lostech. Unlike the current offered special missions which you have no control over, they just appear at random, the MercNet Mission board has dozens of goal/reward based missions. 'You', pick the reward you need and then it's just a matter of can you succeed at pulling it off? The greater the reward, the greater the difficulty scaling. You could never say you had nothing to do then because there is MercNet and they have new things you need.
I do these generated missions, but I am always wondering why?