In a nutshell, early action applications come with many of the same benefits that early decision plans do, but without all of the baggage. As a refresher, those benefits are: receiving your admissions decision early (generally by or around Christmas time), having a higher chance of being admitted, and demonstrating an interest in a college.
The first thing you need to do is identify which of the two tests is the best fit for you. Let’s get one thing out of the way—which test you focus on is up to you. No college has a preference for one test over the other.