I had to use it in a power out recently. I wired it from the 30a rv plug into two power conditioners then to the house. I had to make special plugs. Voltage stays between 120.1-120.9v (measured with a ohmmeter while loaded- 3 refrigerators and lights, radio). The conditioners did a really good job cleaning up noise. The radio was perfect. I still haven't tested it with anything more expensive.
Ran everything about a hour and half without any trouble. This type of setup isn't stock but the voltage stayed stable with the fridges kicking on and off.
I didn't get a scope on it like I was planning as power was restored quick unfortunately. It is quite loud. I'm planning on building a enclosure for it with a big metal fan and maze the exhaust so my neighbors don't kill me. For the money, this was great. It runs everything at 120v on L1 and L2. All 220v split phase appliances were turned off at the breaker as well the main to the transformer. If you don't understand the trouble this can cause, it's not worth doing.
tldr; Overall, happy. It's loud as any non liquid cooled motor can be, but did exactly what I needed in a power out.