Well, something that seemed kind of awful to me:
I'm playing as Ramiro, vassal and brother of Antso, King of Navarra. I finally decide I'll declare war and depose him as king. (He's got about 7 or 8 kids at this point.) I win the war, and go to peace out.
It tells me that one of his sons is now going to replace him, Fernando something, instead of me. I click okay, to see what happens. The king is deposed, his son takes the throne, and the the king that was deposed takes over my county. I immediately start playing as (the former) King Antso, now controlling the same territory I started with.
This seems outright absurd to me. Ramiro just won a war for control of the Kingdom and upon successfully winning the war, loses everything.