Tom,

The question is:
Is G.R. a viable, cost-effect tool that benefits society,
or an over hyped,. limited application, model?

Probably not.

Would you only learn something new if you could apply it to your job
so that you can get a raise? If not, why waste money on a book?

Just because the knowledge does not directly benefit society
monetarily does not mean it is not worth persuing. Man is a curious
animal. In my view, far better is it to satiate this curiosity than to
save a few extra bucks that you would spend on things that don't
really benefit society anyway.