All three of those were outsourced and not done by Gearbox themselves. The last DLC, Tiny Tina's Assault on Dragon Keep, which is the best one, was done by Gearbox and it is definitely worth it. At least, that's my opinion on it.
I did however, enjoy Campaign of Carnage, Mister Torgue had me tearing up. --- Peace Sells...But Who's Buyin'? GT: JusttBlaise