David proved to be a bust LAST year, i.e. before Porter arrived. And Young didn't show enough to warrant considering him for a starting spot, hence the Saints drafted Porter in the 2nd round (Young was a 3rd rounder in 2007). The Saints' only real move to improve the secondary, outside of drafting Porter, was bringing-in the inconsistent Randall Gay from the Patriots. So again, Porter didn't have to compete with much and was given the lion's share of PT with the starters in camp as a result. But as I acknowledged, he's been playing well.
He's barely played because he's buried on the depth chart. And in his most extensive action, yesterday, he played well.
So the Saints' FO was dumb for taking Bush with the 2nd overall pick, but smarter than the Bills' FO for drafting Porter. Okay.