User blog comment:Drkdragonz66/MW3 Content Collection 1 & 2 and Black Ops DLC reduced to 600 MSP next Tuesday/@comment-25496444-20120628101249/@comment-1263839-20120628182413

Call of the Dead = Open, very easy, good for casual games

Shangri-La = Tight packed, difficult/puzzling, numerous enemies, inability to get power-ups without further risking life, good for games you are willing to put work into.

My personal favourite of the two is Shangri-La, but Call of the Dead is always fun. It's really just based on what the two contain (as stated above).