In the end though, the biggest qualitative difference from this year and last is the safety play and the pass rush, both areas with serious personnel change from 2011.
Not too sure why you'd think losing Orakpo wouldn't change this defense? Is coaching the reason our pass rush fell off a cliff this year? Doesn't it seem more likely that losing 2 of our top 5 rushers is the difference from last year to this year?
The Green Bay comparison is interesting, but I don't really see it as apples to apples, at least offensively. Defensively, I'd have to know their roster a bit better before commenting.