So I took this class before taking quantum because my advisor told me it wasn't necessary background information. That is not the case, knowing quantum would have made this class significantly easier. That said, Vucelja is not a great lecturer and frequently makes simple concepts in the book difficult to understand. When I took it, by the end of the course it was very common for people to come in and read the textbooks and ask her questions about their reading rather than listen to her lecture (which I'm sure didn't help her confidence). However, the graded part of the class was not hard, as the homeworks mainly required hunting through the book for the correct formula and most could be done in ~1 page. The tests also weren't hard, as the problems were rederiving something done in class or the homework. Since you're allowed a note sheet for each exam, this wasn't that hard to do.