For the 0Ls, I'll share the class/prof combos I had and whether supplements are helpful:
Greenfield/Contracts - Supplements are unhelpful. In fact, I think they may be counter productive. Greenfield is very particular.
Hollander-Blumoff/Civ Pro - Freer lectures/supplements are good and very helpful for me, even right up until exam time.
Drobak/Property - Didn't use supplements, didn't do as well as the other classes, but I still think they are unhelpful (I slept through a lot of this class because of its after-lunch timing)
LaPierre/Con Law - Chemerinsky is helpful only to the extent it provides big-picture overview of the doctrines. LaPierre spends half the semester on Commerce Clause and gets into super nitty gritty detail. The supplement won't provide the coverage you need, but does a good job of putting everything in perspective.
Tamanaha/Torts - Supplements are not necessary at all. Tamanaha is very good at telling you exactly what material will be on the exam and teaching for the exam. Just pay attention in class, take notes, and you'll be just fine.
I had a visiting professor for Crim Law, so I don't have helpful information there.
Remember: Supplements are only helpful to the extent they improve your retention/understanding of the material. If you pay attention in class, takes notes, and do the readings, you'll only need to turn to a supplement once in a blue moon, if at all (the better the professor, the less necessary a supplement is, generally).