I agree that Hunt had character flaws that went well beyond any problems Raji has, who, despite having some motivational problems, isn't a bad guy.
I do not think Raji's ineffectiveness has been overblown, though. If anything, it's been understated, and hidden behind the idea that "he's just asked to take up space."
Raji graded out as the 44th out of 45 qualifying DE's last year. He graded out negatively in run defense in every game in the last half of the season. In his sole year as the NT in 2011, he graded out as the single worst NT against the run in the NFL.. He has had flashes of dominance, but in general, since 2010, he has been really, really bad. As I recall, he actually set an NFL record last year for the worst snaps per tackle of any defensive player in the history of the NFL. As far as the eye test goes, one needs only review any random snap from the second half to see that he no longer commands enough respect to demand double teams, as a single guard is easily enough to keep him contained.
I wouldn't touch Raji at $3.5M, particularly coming off a major injury. At this point in his career I wouldn't be willing to do anything other than a 1-2 year deal with a really low base and a great deal of incentives.