My view is that they are useful, if used correctly. I think they CAN be a moral hazard-if you are really busy it's tempting to just read the brief instead of the case. Maybe that even works for some people, but I believe its much better to read the case. That said, I found them to be quite helpful when preparing my outlines near the end of the semester. Of particular use is the black letter law, where they pull out the rule. It's not always perfect (especially in the context of how the particular professor handled the material in class) but I found it useful for forming my own brief rule statement for each case.