The fresh water hose connection on our previous 5th wheel was inside a small compartment. Trying to thread the hose coupling and tighten it enough to get a leak free connection was a hassle. A quick connect adaptor was the solution.
Now, even though it is much easier to connect the hose on our new fifth wheel, I still use quick connects.
Most RV manufacturers build water pressure regulators into the plumbing. If this is the case with your motorhome, travel trailer or fifth wheel then you won’t need to add another. But having the regulator at the faucet takes the pressure off the hose too. – Steven Fletcher