My $.02:
1)If this is going to simply power a bunch of iPads and iPhones and similar devices during a power outage or camping, there are far better and cheaper solutions under $50 like the Anker power banks that will fully charge your devices 4-10 times. Buy 2 banks if you need.
2)If this is going to be powering something much larger like a tv or mini fridge, mmmm, ok, but it's $500. Do people really need a $500 power supply? I'm sure there's a niche somewhere out there. And depending exactly what you need to power, you can buy power banks for $120-$175 that will charge a laptop 1-2 times.
I like the idea of this product to be able to power/charge more power-consuming devices as well as be silent, but $500 is really steep. If it was more like $250 I would buy. Maybe it will just a few more years to get to that pricing. My use for such a product would be to power my desktop computer and/or monitor for an hour or so when our power goes out. I have UPS systems in my house but they only power the desktop and monitor for about 15 minutes. The UPS cost about $100. If the power went out, I would just plug my UPS into the Jackery after the UPS dies.