I will say this about many of the systems in the OP's post.
I've seen their adds. And I've visited their websites
They talk like they can run everything in your house in the event of a power outage... They can't. Now they might run the Fridge for one cool down cycle say 4 hours into an outage but they are no way good enough to last say 18 yours (The last power fail near me (NOTE near. as in one building east, I had power).