Ultimately, what you need to take away from this is that Army of Two is a co-op focused game, much more so than even Gears of War. If you pick this up, you absolutely need to be playing with a friend. It's borderline broken when playing alone, but if you are taking down tangos with a buddy, it becomes a much better and unique, experience.
Pros: Great co-op mechanics; decent customization options; looks pretty.
Cons: Atrocious partner AI; it can't decide whether it's serious or goofy; it essentially requires a friend who also has the game before being good.