Onan 5500 LP propane vs Champion 75537i Generator

Our Onan LP runs both A/C units. I don't think the Champ will, so that's probably the metric you need to consider. However, I will say that we have not camped anywhere that we needed 2 A/Cs to keep cool. If you were in Phoenix this past month, you'd be wanting the Onan.

I haven't calculated the GPH usage of the genny. On a recent dry camping trip we ran it 2 hours a day and used propane to cook and to take the chill off the bus in the morning and went though about 15 gallons of propane in 10 days.