She is boring. The class material is boring, but she is even more boring.
The grading for labs is barely explain and when you go to the instructors, they confuse you even more. People I know get low grades and P/D/F the next semester, if take it at all.
Professor Heller is a nice person, but boy is she unhelpful! When you come into her lecture, you see a bunch of slides and her talking on the background. Well, if you hadn't read the book the night before, she will make no sense. So read the book - then at least you will understand what on this planet Professor Heller is talking about!