It's always a tough one balancing the lack of any top 25 wins for a team like Mississippi State versus the piling up of losses for teams like Stanford with 2 outside the top 50 and Duke with 3 outside the top 50. I used to think that top 5 teams shouldn't ever lose to teams outside the top 25, but only UConn, USCar, and Maryland can claim that fact, as ND lost to Miami, UTenn lost to Chattanooga and Texas. Duke has as many wins against the top 50 (8) as Oregon State has had games, and normally Duke's 8-6 would be considered at least on par with Oregon State's 5-3, but when you add in the 3 losses for the Devils outside of the top 50, things get fuzzier.
Teams like Duke that have results all over the place are always harder for the committee to evaluate. You win a quintet including Louisville, UNC twice, KY, and Syracuse, so you must be pretty good, but you lose to freakin' Boston College, Georgia Tech, and NC State, so you're not very good. If you like Duke you point to the best wins; if you don't like Duke you point to the bad losses.
At the very least, teams like Duke provide a lot of good stuff to argue about.