All excellent points by Triangles.
I'll add - if you are thinking about charging an FFE or other electric car with the generator, you need to test it first. So many of them do not work for that purpose. It is almost impossible to predict if a generator will charge an electric car just from specs. There are so many issues to consider.
And to reinforce - noise, don't underestimate the noise factor. If you are going to use this for a long time, what could be acceptable noise for 10 minutes, is outrageously loud for hours. Quiet is very expensive. Loud is cheap. Power ratings are only part of the equation - you can get obscenely high powered generators at Costco for almost no money. Except they sound like a race car idling next to you. If you are going to have that generator far away from you, that's fine. If it is in a construction site, probably OK too. But if it will be used at home or around people, totally unacceptable.
2014 Platinum White FFE (Turning in mid Dec. 2016 25,000 miles)
2013 Ingot Silver FFE
2012 Titanium ICE Focus
2014 Tesla Model S 85