Cunningham has proven to be a pretty solid player, when healthy. He's average at rushing the passer, and above average at setting the run, in my opinion. If you've seen him in person, you'd see that he is HUGE in terms of body mass and frame.
At LDE, while I like seeing Cunningham get some time there, Ninkovich (while undersized) has him beat in rush potential and containment. Not to mention, Cunningham's niche so far has been to line up at DT on 3rd down and attack. I think that should be his role going forward for this team. He can become the player Jonathan Fanene was supposed to be for us - a DE by all measurables, yet has the speed, strength, and frame to eat up blocks and blast through guards when he needs to as a DT.