The course is way too short. Less than 1 hour of video material (for the 4 weeks combined!) is far below average. The INCOSE writing guideline, which can be bought on the INCOSE webpage and which is listed as recommended reading, is more than enough for most people to grasp the concepts behind textual guidelines, and to write and review textual guidelines themselves. The INCOSE guideline even includes lots of examples. Pushing his own pricey book (which is not at all required to successfully pass the course) at the end of each and every video becomes fairly annoying after 2 or 3 videos and should have been left out completely.
Apart from these issues, the course content is good. It is based on the INCOSE writing guide (of which dr. Ryan was a co-creator) and ISO 29148. Solid and valuable material, but as stated above, the course is too pricey to make it worthwhile for some people.