We are in the EXACT same predicament, right down to the cat/dog coming along.. Virtually impossible for anyone to make that decision for you as you can see there are many opinions on the subject and pretty much all true comments above.
We are focusing our efforts on best FLOORPLAN within our budget and chassis/engine later. You will go back and forth with pros/cons for years otherwise and we are finding it tough enough to choose the floorplan. LOL
We are trying to keep in mind the travel and camping we typically do... For example the less engine noise on the diesel (coach and generator) is true but if you are like us and 1000 miles away from the closest mountain then I don't know if I care about engine noise. Haven't found any gasser too much louder than my 1/2 ton pulling the current trailer on the flats. Would be nice if the generator wasn't under the bed but WE seldom camp without full, reliable power so.... Nobody ever thinks about where the Gen is located until they want to use it while sleeping or it automatically starts in the middle of the night due to the AC.
As you can see, now I'm starting to go back/forth. LOL
My $0.02 - Happy shopping.