Law School Early Decision deadlines are coming up, so it's a good time to revisit this question: Under what circumstances does it make sense to apply ED? (And for these purposes, I assume "Early Decision" is binding.) A couple of thoughts:
1. The Early Decision commitment will not overcome an otherwise weak application. If you're less than competitive for an ED school, they aren't likely to snap you up out of the early pool. Rather, they'll probably want to roll you over into the regular pool so that they can see how their applicants are shaping up that year. For that reason...
2. If you're in your fall semester of senior year, applying Early Decision makes sense only if you are already at your strongest academically. You still have more academic work and grades ahead of you, and many college students do their most interesting and important work senior year. People who have upward trending grades throughout college would be cutting off a sizable fraction of that trajectory. Unless your GPA is already at its peak by the end of junior year, it might make sense to reconsider your application timeline. Especially if you have academic weaknesses to mitigate from the earlier part of college, you'll want to show them a stellar senior year's worth of grades, or a last a full semester’s worth from the fall term.
Another option: If you're not at your strongest at the start of senior year, consider putting off your apps for a cycle so that you can apply with the benefit of your entire senior year.
3. If a school doesn't offer an ED option, and it's genuinely your first choice, it might make sense to commit yourself anyway. If you would definitely accept an offer if you received one, let them know. All else being equal, they would rather have students who really, really want to be there. If you make that promise, though, treat it as if it were like any official binding ED commitment. In both cases, it would be bad form to back out of that binding commitment. And if the thought of committing yourself to a school makes you ruminate about the options you might be closing off, or if you know you're the kind of person who would have buyer's remorse, a binding commitment might not be right for you.
4. If you are accepted into your ED program, do whatever it is you agreed to do when you made the binding commitment. Does your ED school require you to withdraw all your other applications if you're admitted? (That's the typical case.) If so, withdraw immediately. Not next week. Not two months later. Some applicants are tempted to leave their other applications in place, mostly out of curiosity ("I know I've committed myself, but I really want to know if I would have gotten into Yale"), but sometimes also in the hope that they can "upgrade" if a better offer comes along. Neither situation is kosher if you're required to withdraw. Plus, your "upgrade" school could very well take a dim view of you reneging on your ED obligations to another school and consider withdrawing your offer. The law school admissions world is a small one.