This CSS course introduced me to concepts that I never learned from other courses. Most courses will give you a cursory introduction to things like flex and grid. But they won't explain margin collapse, layout algorithms, stacking context, and other concepts that are needed to understand why CSS acts the way it does.
Most developers hate CSS because they were never taught these underlying principles. Instead we memorize tricks and concepts to try to keep out of hot water. It's like only learning git add and git push. If that's all you know about git, you will find yourself in some deep trouble unable to solve a basic problem in the future.
The course itself is cleanly split up between explaining the technical sides of CSS and building components or exercises. I think this strategy, while it makes sense structurally, makes the course more boring than it needs to be. Each of the 9 modules and it's containing lessons are the same formula, over and over, just for different topics. After the first couple of modules I found it very difficult to focus for more than a few minutes.
My suggestion would to be to mix the technical explanations into lessons that make up a larger project. I know I say this often, but starting from scratch building some basic layouts with the flow layout and gradually upgrading that and giving it more detail with newer layouts is a great way to learn and keep the context from previous lessons.
When everything is split up and taught from the ground up for every module, this becomes grading and it starts to feel like you've already done each module because each one feels the same as the last.
The course did, however get me excited for CSS for the first time. My head is full of ideas for building component libraries and finally redesigning this site.
My rating system is based on a lot of things. Presentation and detail are very important. Because of the repeating formula approach to the course, it has more text to read that it has video. Both the video presentation and the use of interactive code in the course are very well done. (Although I am personally against the usage of interactive material as opposed to building real projects that the viewer has total ownership of.)