To get back on topic and add to the OPs question--
I used the little brass regulator from camco or WalMart for years but
as mentioned, it restricted the flow and at times I felt like it let the
pressure creep up when water was not being used.
If I turned on a faucet I'd get a burst and then low flow.
I finally sucked it up and bought one of these
RV Water Filter Store: Standard Filter Canisters for Whole RV
I chose the Watts Brass Model 263A Adjustable Regulator, 10-65 range, 4-4.5 gpm
It's repairable meaning you can get kits to rebuild them if ever needed.
It works GREAT.
We left one of the other cheapie regulators on the water post one time
and now my wife always asks me if I've put the regulator away when
we're packing to bug out.
IF you're low use part timers the camco one will get the job done.
If you camp often and especially if you shower or want to fill a bathtub,
you'll be glad to have one of the full flow Watts models.