I have a Watts adjustable water pressure regulator......4 gpm max flow and I keep it set to 50# static pressure.
Never had/used a regulator before as camping was rarely at any place that had continuous water hookup.
But when we went FT I got one based on reports of CGs having high pressure.....which we did find true.
But after a little more then a year on the road we stopped using 'city water' connections due to a fitting failure in the middle of the night (fitting must have been cracked during original install and then finally blew apart).
$6000 in damages/costs---we went back to using fresh water tank and pump which has a 45# discharge and 'cycles' should a leak begin.
IF one is going to connect to 'city water' then it is good idea to have/use a good quality water pressure regulator at the source to mitigate high pressure excursions at CGs