+1 to what the OP said.
We had an Onan Propane generator installed when we bought the camper in 2006. We had one problem which was brought on when the propane continued to 'refine' in the fuel line, thus gumming the carburetor up with oil. I had to remove the generator and take it in for service.
As for fuel consumption.... I have never run it for such a time that I have sucked the tanks dry. Running the A/C on the generator is occasional as we are typically not in those types of situations. Much more common is DW wants to run the microwave or hairdryer when along the road somewhere, and the convenience of a built-in push-start really pays off. I imagine a gas generator would also burn through plenty of fuel if it was left on for an extended period of time cranking the A/C.
Would I take this rig out to the desert in August and run the generator 18+ hours a day to keep the A/C running? Nope. That would certainly empty the tanks on a daily basis. Would I run the generator to cool off the camper when we arrive at a hot dry-camping location after a day of driving? Sure. And I may run it an hour or two the next day when we return to the camper after a day of activities. But frankly that hasn't happened to us yet. Those times we have gone camping in hot locations we paid for hook-ups, so I just let the A/C run on the campground's power.
Not sure what the OP's purpose is for starting this thread....but I will have to say I have not experienced all the problems the negative hype told me to expect.
Thanks,
-Eric