I believe it is good to try out different value on a specific currency pair that you trade.
Let say I am trading GBP/USD.
using 1 hour chart
I set EMA = 25 , 75
MACD = 20 , 80, 15
How I come to this figure is based on the two main point,
- to indentify trend as early as possible
- to avoid whipsaw.
Just learn from babypips school few days ago …
but these setting might be suitable only for GDP/USD on 1 hour chart.
You might need to change them again for 15 mintues chart for the same currency pair.
My bottom line is to find a value that it will fulfill point 1 & 2 ( they will always conflit each other ) that I feel is acceptable to me.
To answer your question , I think that would be a “yes”,
the higher the number you put , it will react slower to a trend change but will have less whipsaw. Which is what you mention more “sure”
I hope this will help…
I never play with the number for Parabolic sar, so I would leave it to the expert to explain it.