Informative forum. I ended up here after doing a search for the Champion 3100 invertor generator. I mainly plug into shore power (13.5 AC) when I camp at modern RV parks but I go to Oshkosh Airshow were most boondock and I bought a Champion 4k open frame when I got my TT (2007) that mainly has been used when the power is out at home and a few days a year at Oshkosh. I wanted something slightly quieter (for me) and something lighter to handle when camping there. I originally was leaning toward paired 2k invertor generators to have more headroom with loads but after stumbling on the 3000 watt offerings I'm considering one. If I get one to lessen the load, noise and fuel consumption I will turn the hot water heater and frig to propane when running AC.
To Champion's credit it is a durable generator. After 7 years of use I just changed the oil, cleaned air filter in the spring. The recoil cord broke 2 years ago at home during an outage where I pulled too aggressive too many times but I fixed that after watching YT videos on replacing cord.
I saw Briggs and Stratton has a selection of generators but haven't seen much reviews on them.