So I have finally made it through the campaign with my wife. I was right about not getting all those audiofiles... I didn't even get half of them! I also noticed that getting some of those weapon achievements are going to be difficult because you have to get them in one level. I would imagine co-op makes this a little more difficult as well. It was fun but seemed a little on the short side. I guess I'll see what happens when I try this game solo...
There's just one drawback to that though. . . She never ever likes to sit through the cutscenes, and once she's gotten to the end of the campaign, she'll never play it again. I like to play things over and over so I end up trying to get through everything again on the harder difficulties (if I can) :p
Same here, or at least until I get all of a game's achievements. I doubt anyone would want to sit by while I die on Legendary Halo 97 times in one mission so I can get an achievement. That would be masochistic.