Compared to 123A this class is apparently harder and less organized. Everything after the Boltzmann transport equation and correlation function seemed all over the place and disconnected from each other. Even though Prof. Schwartz's exams are usually fair, the final was horrendously hard, maybe partly because of the disorganized materials.

Took 123A&B

The class is hard simply because the subject matter is incredibly hard.
However, his lecture is clear and understandable--an amazing feat on its own because of how hard the subject is.
Notes are provided days beforehand so you can print and read it during lecture without writing scrambling to write notes---which helps a lot.

Overall very impressed with his teaching skill