The stealth note is the one I prefer.
This goes against those that like a nice rumble to those that like something shattering.
You have to ride a m/c to where the exhaust note is about the same sound as the wheels on the pavement.
I assembled such a bike back in '47 & sold it to an elderly person, later found that same one & bought it from the old chap that retired, rebuilt it & rode it, as a probable vintage bike, up untill I was in dire need of money to keep my farm going in '66.
You find your neighbours asking if it is electrically driven & many other strange questions.
The bike was a '47 LE Vellocete 175cc SV flat opposed liquid cooled twin, with shaft drive, s/arm suspension & chassie instead of normal frame. Crumbs it was even hand starting & 3-speed hand shift, but so quite one could hear the breaker points clicking away.
Obviously this is why I prefer to leave the exhaust systems on my bikes stock, YET as one that was deep into dirt comp & road racing I have heard a lot of LOUD bikes --legit on the circuits.