I can't say anything about the resistance to stress over a long period of time. It passed my limited stress test. 1000W peak power is a joke, but aren't they all in this price range? I like that the fan starts and runs for a few seconds when the inverters are on. Lets you know it's working. I would only use this little inverter in an emergency and for that purpose it should be fine. If I had relied on it every day, I would have bought a much higher quality device. you know who it is Test: I used a Kill-a-Watt meter to load this 500w inverter. Drainage pump with a capacity of 1/6 l. Loads are already running.