Some of the side quests are
really good. Having looked back at what constitutes the main campaign, it's actually pretty short but the game forces you through chokepoints where you need to accomplish certain side activities to progress with the main story, i.e. where it presents a list of objectives some of which are just "???" leaving you to just engage with the world.
Fortunately, we really enjoyed doing the side quests but I bet we missed a bunch because I think we only visited perhaps three hamlets that the main quest, or key side quests, take you on. The completion rates around around 65% which gives you an idea. I may actually go and finish which I assume is the final of Sebastian's quest, just to get the third curse. You know, the
good one..
Whilst we didn't use Crucio much, we used Imperio a fair bit. Weirdly, none of the companions commented on it, which is good because it's handy to have a troll on your side, or a giant spider.