The only real experience I have is writing an application (using Node.js) for my MSc course which was an AJAX application for interacting with Amazon SimpleDB. It was fun to write and weird that I could use the same language from the front-end to the back-end.
Back to the React course, I completed it over a week, taking my time to break things (it’s the only way to get an appreciation for how things work!). It’s a really nicely laid out course, where you build a market for fish (a lot more exciting then it sounds). It doesn’t really cover any CSS or HTML, so you should at least know that before starting.
What I really liked in particular was the build tools, including Gulp. Gulp is like Make, Maven, Gradle, Ant etc. It’s very flexible and fast, with hundreds of modules on Node Package Manager to choose from. Part of building the app, you can make the assets (HTML+CSS etc) smaller (minification), run a web server and open your browser with the app automatically. Combined with a nifty tool called BrowserSync, it’s the fastest feedback cycle I’ve probably ever had. That makes it fantastic if your new to this kind of thing, nothing inspires happiness more than seeing instant results!
All in all I’d very much recommend it. I even re-wrote Grogan Burners (My Fathers business) website to use React components after!