There are many benefits of applying to college Early Action (EA), and only a few cases when applying early may not be advantageous. While Early Decision (ED) programs are exclusive and binding, EA programs merely allow students who apply earlier in the year (typically before November 1st) to find out if they are accepted to a given college earlier in the Winter (typically before the end of December). Unlike ED, students may apply to multiple schools for early action, with only a few exceptions like Stanford and Harvard which restrict students to apply EA only to their school.
Finding out a decision in December instead of March takes a lot of stress out of the student and their family's lives during the Winter. Many EA programs also have a higher acceptance rates than regular decision, although the increase is not as consistent or dramatic as with ED programs.
The only times when I recommend students do not apply EA is when we feel they need their Senior year Fall semester grades, or recently taken SAT/ACT scores, to strengthen their application. However, even in these cases, it may be wise to apply EA to a likely, or safety, school so they have an acceptance letter early in the Winter and can relax knowing that they are going to college next year.