I was just about to pull the trigger on the open frame Champion 3500 from a big box retailer because it was a great price (less than $300) but the specs said it ran at 68db. I went to a tool rental place and had them start an open frame genny with the same Db specs and 68Db's is loud. Too loud even 20 feet away from the camper.
I'm glad I waited -- now Champion has a dual fuel inverter type 3400 max watts that runs at 59Db's. I'm waiting for the Fall sale and I'm buying that sucker. It's quite a bit more expensive ($1k).
BTW -- decibel rating is progressive. There is a big difference bwtn 59Db's and 68Db's.
There are some other off-brands sold by big box retailers that have great prices and horrid reviews. I'm pretty convinced Champion is a great buy dollar for dollar. Honda/Yamaha have stellar reputations but stellar prices, too.