I thought one very profound observation/recommendation was that trial lawyers should also teach and Professors of Law should also try cases (as he does) - much insight from each of these disciplines will have a positive influence on the other.
Dershowitz is someone who lots of people hate. He has defended despicable people for despicable crimes. But there have been many trial errors and some of the people whose appeals he took on after having been convicted were not really proven to be guilty and may well have been innocent. He opines that most instances of perjury in courts are committed by law-enforcement personnel. Also he is pro-Israel and that is a hot issue for some people.
He has written lots of books; I'm definitely going to read some more of them.