One of the biggest drawbacks of O'Brien's departure at this point is that Penn State's potential superstar quarterback has lost his mentor. If there's anyone who knows how to groom an exceptional quarterback, it's Cutcliffe. He served as offensive coordinator and quarterbacks coach during the Peyton Manning era at Tennessee. Shortly after that, he mentored Eli Manning as the head coach at Ole Miss. Cutcliffe obviously knows how to handle a quarterback of Hackenberg's talent, but throughout his 31-year coaching career he has proven his ability to bring along quarterbacks regardless of what he's had to work with.
Cutcliffe not only wins, but does so the right way. He graduates players and works to prepare them for life after football. He makes sure his players carry themselves in a way so that alumni are proud to have his student-athletes represent the university. Whenever he receives any well-deserved credit, he humbly finds a way to redirect it to praise his staff and players. He's made a career in the college game because he loves coaching football and molding his players to make an impact both on and off the field. In short, he has the characteristics that Penn State fans demand of any leader.
Sure, Cutcliffe has his drawbacks. For one, he's spent his entire career in the South meaning he has no real connection to Penn State or the Big Ten. However, this could be an advantage as Cutcliffe is very familiar with current Penn State hotbeds such as Maryland and New Jersey, and opens up many more doors in SEC territory.
The most notable detraction may be Cutcliffe's age. At 60 years old, he is likely looking to retire in another five or six seasons. While young and energetic usually trumps experience in the college football world, this criteria should not be held against him. After five or six seasons with Cutcliffe at the helm (and no more sanctions), Penn State would likely once again be one of the premiere programs in college football. Even if there was no one on the current staff who was ready to move up to head coach, Penn State would be in much better position to pluck a highly-regarded coaching candidate who would likely not even consider Penn State at the current time.
Right now, Penn State desperately needs someone to take what O'Brien has left and continue to move the program forward until the Nittany Lions are on a level playing field with everyone else in the Big Ten. Cutcliffe is more than capable of doing this, and would have the program hitting on all cylinders by the time the team is ready to fight for a national championship with 85 scholarship student-athletes.