It is necessary to have a generator in a 5th wheel, I know some have them some don't. We are looking to go to a 5th from our class a and we really don't use ours a lot now.
We have had the Onan LP 5500 for 11 years. Fantastic convenience. It is kind of like the Washer/Dryer, Dishwasher, Satellite dish...nobody actually "needs" them, but they make for a comfortable rig.
