We've got a Predator 3500. When boondocking we use it extensively for drying clothes and to run one AC.
I must say it has not been flawless.
The first issue was soot at high elevations. It was jetted way too rich to run much over a mile high. I put a 68 jet
in it and it now runs better than it ever did. That being said you do have to fiddle with it a little when cold. If you jump straight from start to run it'll die. Start is nothing but the choke so I back it off slow and it does great.
The second was an exhaust valve pulled through the spring keeper.
It appeared that it wasn't sufficiently heat treated. I bought Honda replacements (the engine is a Honda clone) reset both valves and it's been running like a Swiss watch ever since.