My absolute favorite part of it is the ability to send sons away to join mercenary bands. My characters usually have an absolutely ridiculous number of kids so I have more control over my next playable character, and I switch to elective governments whenever possible. So I send each and every son off to make a name for himself and whoever comes back victorious I groom as my heir. I actually wish there were more sub-mods that added things like this, with different quests you can send your kids off on when they come of age to prove their worthiness to the throne.
It brings me back to reading Blue Moon Rising by Simon R. Green as a kid. In that book a king sends his second son on a quest to slay a dragon. All under the assumption that he'll get eaten like a chump and no longer be a threat to the king's firstborn son. Except the second son befriends the dragon, returns to his homeland with the dragon at his side, and becomes a total badass during his journey while his older brother kind of just sits in the corner moping about how he's supposed to be the cool one.