It definitely is more about managing a medieval family
It is not even that.
When you first play it the first thing you will feel is disappointment because you basically can only do 10% of everything you would like to do. 1% if you have an imagination.
So whatever you think of Crusader Kings right now... take off 10% and that is the game you are actually going to get. Which for some that is enough and makes an excellent game.
Also take Neonivek's post with a grain of salt because he's grumpy about every game since they're not his ideal dream game.
+1, Neonivek has never said a positive thing about a video game in his entire life. I think he might actually not like them. In this case, I think he thought it was going to be something else, but we'll never be able to fully understand what that is.
CKII is, in the simplest term, a feudal rulership simulator. If you liked the high end politics in Game of Thrones, you'll like CKII. It's essentially just another grand strategy Paradox game. If you've played Victoria or Europa Universalis, you kinda know what to expect. It's definitely easier to get into than those titles, however, and also more intuitive than CKI.
The family management isn't actually the design base, I don't think (though it is doing the best job of it of any game I've played). It exists because of its importance to the historical era.
At $10, I would definitely recommend it without hesitation. At $40, there's no reason not to play the demo for a little while. When it first came out, I pirated it first, and then immediately bought two copies so my girlfriend and I could play together. After getting the expansion packs, I don't at all regret spending over $100 on this thing as I often have with bigger game expenditures.
I will say, though, that actual crusading doesn't play that big a part in this game. And it plays a smaller and smaller part with every expansion they release. I can't even remember the last time I went on one.