Wow, pretty harsh responses for a fair question. I completely agree that while you are much more law school savvy in your third year, motivation is harder and the course material is often harder as well. Also, at least at my school, we were still graded on a curve. So while I was much better at performing in exams, so was everybody else. I think the biggest reason why third year gets the reputation that it does is because while it may not be that much easier, your grades count WAY less than they did in your first year. Most students at the top schools already have jobs lined up and I'm betting it would take pretty bad grades for an employer to revoke an offer (any stories?). But for students that don't have an offer lined up, I would not get complacent in their third year.
Just my two cents.