Leviathan gets two thumbs up from me. Dug it a good bit. Cool story beats and some sweet new scenery. There's some pretty obvious padding, but I found it easily forgivable. Haven't re-beat the game, so I can't speak to that effect.
It would seem based on my playthrough that only Conspiracy Theorist is a missable achievement, for what it's worth. Interested for others to weigh in.
Also, after playing so much multiplayer, the single player is even easier than it was before.
Last edited by ActionKazimer; 08-28-2012 at 09:25 PM..