This year we decided to do a "Tió" for our kids. It was great fun having the kids give it many different kinds of food and watch it magically disappear the next morning (extra points for creative placement of leftovers).
Our youngest was really scared though when we started to sing the song and wack it with a stick and was telling us to stop hurting the poor log. After the candy appeared he got over it pretty quickly.
All in all, I think this is a tradition that we´ll keep. The caganer in the nativity scene is also "un must" as they say here.