Barbri is the bar review service I think, that deals with substantive subject matters, the other two are more what to do at law school. You will eventually have to take a bar prep, 99% of students use a bar review course whether it be barbri or micromash or whatever, unless you are insane and think you can study for the bar with no material. People who sign up for barbri get free barbri information, outlines, and can watch videos for the subjects they are taking.