I am going to tackle the subject from a slightly different angle. As I explain repeatedly in my book, "Law School Labyrinth- A Guide to Making the Most of Your Legal Education" (Kaplan Publishing, 2009), in law school the process is infinitely more important than the output, at least as far as outlining is concerned. This means that outlining is nothing more than a means to an end- the end being comprehensive memorization of the "black letter" law. The term "black letter" refers to the actual law of a subject, especially the common law; something law professors will generally not declare. As with most things law school, you figure it out for yourself.
Certainly, outlining serves other purposes, such as helping students begin to organize their thinking about a particular subject in a lawyerly manner. However, I would like to limit this blog post to the memorization aspect because it is simply so important when things really count in law school- at exam time.
So, which commercial outlines are best suited to help law students memorize the law? The answer is (again, as with most things law school) "it depends." It depends on where you are in terms of the breadth of your knowledge on a particular subject. If you have been following the Socratic dialogue, keeping up with the reading (and following the casebook's table of contents carefully- another suggestion from my book), regularly digesting the material and recording your digestion in the form of an outline, you may not need much, if anything, in the way of a commercial outline.
On the other hand, if you simply aren't following, a good commercial outline may be exactly the roadmap you need, in order to begin to own the material. A commercial outline can also fill in the gaps that the casebook or the professor inadvertently (or intentionally) create. Finally, a commercial outline can serve the useful purpose of helping you to check your thinking and progress. So, in some cases, a very simply and high-level outline may do the trick. In other cases, a detailed outline, complete with annotations may be in order. Or, a series that is a bit more "interactive" that includes questions and practice exams may be that extra edge that enables you to "own" the material.
In any event, despite law school lore, there are no "holy grail" commercial outlines. More importantly, in law school no amount of money invested in outlines can replace the basic grinding required, in order for the student to learn and be able to work with the material in such an effective way that they write those critical "A" exams. And by the way, that's often what we lawyers do- we conduct research, we read and reread, we grind until we have sufficiently mastered a subject in order to render effective legal advice.
In "Law School Labyrinth" I describe the Pyramid Outline Method, which is a study method for law students that enables them to work effectively throughout the semester, avoid classic law student time-wasting dead ends and increase their chances of success. I truly began to understand this method only after I had successfully completed two bar exams.
So, a simple answer to a complicated question. The use and choice of commercial outlines is a very personal decision to law students, that depends upon a variety of factors. But again, a commercial outline alone will not earn you an "A". You are going to have to work extremely hard and smart, in order to master the material. A commercial outline can help. But a commercial outline can never replace good, old-fashion hard work.