This is a very nice course, it's part of the advanced machine learning specialization so it would make sense if the lecturers go fast through some mathematical intricacies. lecturers are not obviously native speakers but who cares, they speak clearly and that's all that matters to me (subtitles were invented for a reason...)
if you are used to Andrew Ng's way of introducing concepts you might dislike this one (at least at first). Andrew's philosophy is to "democratize" AI education so he tends to simplify concepts(especially maths) for better digestion.
These guys do not do that(and there is nothing wrong with that...) because, i think, they address a different audience
After all the specialization's name is ADVANCED machine learning, keep the momentum HSE, you're doing great !