Re: Water pressure
I would say no. Water pressure will be the same big or small, however IF one was able to have a large enough flow on the inside of the RV(which I think not) then you could out run the ability of the smaller size of the quick disconnect to keep full flow and then have reduced pressure. The only time you might have enough flow that I can think of is dirrectly filling the water tank which could have large enough pipe to keep up with or out run the feed of the quick disconnect.
LEN