I went from a bumper pull to a 5th wheel, both i did frequent overnight stops. with the trailer it was fully accessible while closed up so we would frequently pull over in a pull out to use the bathroom, or a rest area for lunch etc. if stopping for the night (we go to several places that are a 1.5 day drive so I will stop for the night in truck stops, Walmart, etc) I would just crank down a couple jacks to take the bounce out if the area was fairly level, other wise I would have to unhook. that was a bit of an event with manual jacks and an equalizer hitch.
the fifth wheel is similar, if stopping for the bathroom it is fully accessible, if it is just me and the wife we can get to our bed no issues and we can use the kitchen with the big slides in. if the kids are with us we need to put out slides for there beds. the big difference is with the 5th wheel hitch and the auto leveling jacks if I have to unhook for the night and putout slides its a 5 min job and i only pull a couple feet ahead so i have room to level.
having said that if I have the wife and kids I plan for shorter days and overnight in a campground, its only when I am going on road trips by myself that I drive all day and then pull over somewhere for a sleep then on the road again.
my parents have a 42 foot class A and they have room to do what ever with out putting out slides. but I guess like what was mentioned already thing about how you can use your space when you are pulled over for a quick lunch or nap when you are looking at trailers. fridge, and staples, bathroom and beds should be accessible if you plan on doing this.
Steve