I guess that it depends on the user; Marc Rivalland uses it with a 5-period with great success, according to his book.
Personally I stopped using it; my favourite way was to look for divergeance between price and indicator, but that is difficult to program and, therefore, to backtest.
If you think there is some merit, I would suggest that you backtest it on your favourite instrument over a significant period of time, say, 5 to 10 years, and draw your own conclusions - what may be right for me might not be so for you.
Eduardo