In general, it is said that Moodle is hard to use, because of the GUI complexity. In my personal opinion, it is not that complicated considering that it has been developed for more than 10 years. With investment of a little time, Moodle can be used without difficulty. However, in order to use a lot of features of Moodle in a various situations, it is natural to spent fair amount of time to be an expert user.
Below is the video of iMooc service of Carrot English. It has been developed recently by JinoTech. The service is for English learning. The trace of Moodle is hard to find. Teachers still can use old Moodle GUI for activity generation, but the students can see the simple page consists of two Moodle activities. This customizability shows new horizon of Moodle adoption. Enjoy following video.