Definitely yes if someone want to make a product. So it depend on a purpose of learning.

Too much whip out.

Only works in the book :)

Write any variables first.

I' use with 'normalizr' . This was really helpful. Especially more peaceful when I implement asynchronous logic.

I'm using less design styles based on semantic-ui. Also I use a Radium. I know this is confused way. So there are some rule for our ways. Radium styles are used only for position or size handling such as width, height, padding, margin, top, display .. less css used for global styles and specific dom design. Radium is used only react front developers.