Get this only if you truly enjoyed the first game and want more of the same.
Special random encounters are very few and hard to get, and since they also don't offer any good special rewards, there's nothing really exciting about it. In terms of game balancing, the only thing you'd notice is that it makes things harder for you. You can't hide in Panzerklein mode this time, and they are much harder to kill also, compared to the first game. And there are lots of them to kill! To make matters worst, the missions are geared towards veteran Silent Storm players who have to be really good in calculating moves in order to scrape through the ridiculously unfair scenarios mid-game onwards. In other words, it's more relaxing to drive with faulty brakes.
So, unless you're really fond of the original game's challenge, you may find it hard to cruise through this expansion other than if you think your real life is not stressful enough.
KingLim