AT LEAST IT'S NOT 'MOXXI'S UNDERDOME'
Despite the premise of a tournament of badasses, at least "Campaign of Carnage" is nothing like the oft-maligned "Moxxi's Underdome" DLC from the first Borderlands (though Moxxi does appear here to play a part). Rather than just being a straightforward arena (Gearbox won't repeat that mistake), "Campaign" sends you on quests to track down the leading badasses, who are reticent to give up their positions (to say the least).
You'll fight through armies of biker bandits and airborne cadres of weaponized buzzards, all the while being verbally abused by a hot-blooded 16-year-old badass, a bodybuilder convinced your character is a noodly-muscled wimp, and more hilarious antagonists.
In other words: "Mr. Torgue's Campaign of Carnage" has got personality.
These characters—the obese biker chick, the hotshot teenager, the bodybuilding blimp pilot—make up plenty of the game's requisite funny, though they never quite hit the highs that Mr. Torgue does. That's okay, though.
Here's another way to sum it up: in that official "ask me anything" session on reddit, Mr. Torgue responded to a question asking about the different between his and Moxxi's expansions with the following gem:
"MORE EXPLOSIONS AND MORE BAD GUYS AND MORE GOOD GUYS AND MORE QUESTS AND ALSO I'M IN IT WHAT THE F*CK ELSE DO YOU NEED TO KNOW." Well put, sir.