Full disclosure: I had HPM for conflicts and not fedcourts, but have spoken to others who took the latter and what follows seems to hold true for both.
For starters: there is no syllabus. At the end of each class, he will flip through the book and announce the next assignment. These tend to be on the shorter side, as he thinks most modern textbooks are filled with "useless filler" (he gets points for this, IMO). He assumes your familiarity with the material, so will not discuss it at any length. Instead, he'll ruminate on whatever aspect of the reading interests him. This will be interpersed with anecdotes of varying relevance. He will ocassionally put a question to the class (never a cold call). Important: this is when you need to act like your paying attention. If he sees you staring too intently at your screen or (god forbid) without a book, you will be chewed out mercilessly. After about half the allotted time, he'll call it a day. You'll look at your screen and realize you've taken about four lines of notes. You'll have to teach yourself the rest.
He has a lot of pet hates, including: arbitration, half the Supreme Court, modern law school curriculum ("law and bowling") etc. etc. These make for entertaining rants. By all appearances, he enjoys neither teaching nor the company of students. One wonders why, at his age, he bothers at all.
Think of him as a wheat beer. He has his devotees, but will turn off everyone else. Think carefully before committing to an entire semester of this.