Well just to let you guys know when my power goes out at the house, like it did last night. My champion 3500/4000 watt generator that I posted a link to earlier sits about 50' away from my bed room window. I have 1960s shitty aluminum windows in my house and I could not here it running. It's not big enough to run my central unit so the house was quiet. It does keep all of our outlets powered along with the fridge, water heater, and well pump going.
So I usually set mine 10-15 away from the camper or enclosed and if you have the ac running or even just the unit fan you can't here those champion generators. Not to mention at $400 why not give it a try. I loved my 2000eu honda but I had the same issues you do it just not big enough and the fuel tank is not big enough. My champion will run 12 hours on a tank of fuel running the camper ac wideopen.
Did I mention the damn thing always starts first pull. It was great last night when I grabbed it out of my shop at 11pm and took it out in the rain knowing it would fire right up.