I remember my iPhone, on my desk, turning up because of a notification, then hearing the vibration for a failed FaceID unlock. This very smart system wasn't able to understand that it was looking at a ceiling. So I always ended up having to type my password due to too many failed FaceID attempts. FaceID was highly ranked in the reasons why I disliked iPhones.

TouchID all the way. On an iPad, it's fantastic.