we have the one with the 2 poles that attaches to rear of camper....we only ever use it if we plan to be set up for an extended time period, say atleast a week in the one spot. We've had our trailer over 3 years now and used the kids room maybe 4 times at the most. Touring overnight stops, Weekend and long weekend trips our kids sleep on the hard floor...i can't be bothered setting the extra room up just for somewhere to sleep in at night myself.
As to the ensuite gronk mentions, i don't think we've ever used ours (i have set it up to see how it works though). We have a toilet tent we use that is much quicker and easier to set up for that purpose IMHO.