I think Dr Warren's lecturing style takes a bit to get used to, I found him particularly hard to learn from especially considering we didn't have a text book. I also found that his lecture slides were lacking, and the fact that he doesn't post them before the lecture made it impossible to review the content before the lecture. He also didn't really provide enough examples, and didn't go through enough of the equations and methods he wanted us to use throughout the course. Though, he does seem willing to help if you individually if you approach him and go along to one of his consult sessions. He also isn't particularly good at replying to emails. I think Dr Warren has a wealth of knowledge that he could pass on to students, though I think that the course needs to be restructured around his lecturing style.