An interesting, but a very massive course about Recommender Systems. Lections are very long, and even hough there is no "low information density", as was said before (I totally disagree wih this statement), part of the information could be throught out, regarding the introductionary level of the course.
Being a non-english speaker, I had to pass a long-long hours, lisening to the course, and this fact (and not the course's content) that made it "Hard". I would better call It "harrasing".
I took this course in order to have ability to choose the recommender structure for my site, that someone other is building, so I was not interesting in programming part (that is out in on-demand version). Such a way, I reached my goal by 100%. If I should build It by my-self, this course would be absolutely unsufficient.