So would you go with a built in propane generator today?

I wouldn't have one. When I go camping one of the biggest attractions is having it be quiet. Last thing I want is the roar of a generator or air conditioner, mine or anyone else's.

My fair organ trailer has a 5.5 kW Cummins diesel generator on it that has been flawless through the first couple thousand hours of use, knock wood. I'm really happy when I get to the end of a day and can hit the off button though.