We have noticed a lot of different water pressure at the various camp grounds we visit as well.
I have the other problem of having the water pump kicking 'ON' alot when running off our fresh water tank. Most of our RV CAMPING is off the power grid... I'm thinking about installing an accumulator tank. Was looking at one the other day at LOWES.
Might as well do both mods while I am under the cabinets...
The pressure regulator might also be a PLUS for us as we do the quick BLOW-OUT winterizing method for the water lines when camping close to the end of good weather and running into freezing temperatures at night. My 12VDC Compressor is a tankless type and connects to the city water port using an air port adapter. The 40lb setting might keep the tankless compressor from getting higher than that value and do harm to my water lines... Being the tankless type air compressor I usually have enough time to walk around to all of the spigots and drain the blow-out water while the pressure is slowly building up.
Roy Ken