the Diesel Onan generators are very heavy, loud, and vibrate a lot. My parents Class-A has a three cylinder 7kW in it, and it will power everything, but you can hear and feel it in the bedroom and it is mounted 30' away at the front of the coach. With the LP unit in the Landmark I have easily slept through the night with it running; even though the generator is right under the bed, you can not feel it and can barely hear it running. Additionally a diesel may require a higher reserve capacity to the batteries just to get it started. All I'm saying is that for the type of camping my DW and I and My parents do, they wish they had a good LP generator instead of their diesel unit.