Although there have been some minor issues, the DLC is now out. This appears to have come at the correct time, as it has become apparent many are starting to get a bit tired of the base game's rural Montana. The content within this expansion is likely to appeal to many, but intital reviews seem to be coming on negative-side mainly due to being a bit 'dull'.
On the Far Cry official website it states: "This DLC adventure features new gear and the new Airstrike feature, as well as two different playable modes that will be unlocked after completing Hours of Darkness: Survivor Mode, giving players a limited loadout for a more challenging playthrough, and Action Movie Mode, where a generous loadout delivers over-the-top action." With that, the DLC seems to offer a lot of content. Despite this, reviews so far do seem rather bleak.