The first type, including animation enabling microinteraction is, perhaps, the most useful type of motion design in the aspect of user interfaces. It becomes the way to make interaction quick and clear for the user, often imitating real physical interaction such as pushing the buttons, opening boxes or doors, pulling handles and so on and so forth. Animation of this kind is like health: people do not notice it when it works properly, but understand its importance when something goes wrong. Microinteractions enabled by interface animation are also hardly notable for user until the moment when they face the problem of their absence.
The best features that convinced me to switch to Principle are the Timeline and Drivers, especially if you are used to compositing tool like After Effects. They give you the certainty of always having control over the animation paths and quickly compare your work in progress with your idea in an easy and straightforward way.