User blog comment:Damac1214/Sales of Black Ops II are a "Cause of Concern" for Activision/@comment-67.0.54.121-20121202070525/@comment-92.84.64.106-20121202133405

Player traits, armor abilities, loadouts, bigger kill times, credit ranking system and Arena, etc. All of these changed the gameplay considerably. On the SP side, they revamped the AI and re-introduced the classic elites as main enemies instead of the sluggish bullet sponge brutes. And they removed the Flood.

And equipment is totally different from AAs, which are reusable so they play a much bigger role than the equipment that basically spawned on the map like power weapons.