A good class--hard if you have no background in it (intro bio and some physics), but not too bad otherwise if you're willing to spend the time studying and reading the recitation papers. Prof Firestein is great--he keeps the class interested, he's funny, and if he's a little disorganized, it's never a problem. The class (primarily in the recitations) is very good at teaching you to read research papers. Firestein's tests tend to focus on the important concepts rather than nit-picky details. Part of the course is taught by Prof Yang who isn't nearly as interesting, will ask questions requiring detailed knowledge (e.g. how many neurotransmitters are in a vesicle), and writes small on the board, but is tolerable. Both profs provide practice exams before the midterms, so you have some idea what to expect ahead of time.
weekly recitations, 3 midterms (drop 1), final based on research papers