Just take it on a road where you can stretch the bikes legs a bit and experiment with the settings. I found there was less turbulence for me 'one notch in' from fully extended. It doesn't really come into it's own until i get to about 55 mph and above, after that it gives me better weather protection and less buffetting than anything else i have tried.
But this subject is a bit like tyres, oil, colours etc....lots of opinions, but you must go with what works FOR YOU
