> The only real downside of them is that they seem to drive everybody to this obsession to try to truly understand them.

This. If you only want to understand *how to apply* quaternions to represent rotations, it's not too hard to learn. However, if you want to understand *why* they work, that's a totally different story.

Many of my colleagues still use Euler angles to represent rotations. I always use quaternions, and am a bit baffled why people are so averse to them.