If you’re going to buy a whole house generator, look at the warranty before you buy. Do yourself another favor and google the brand name along with “problems”. At least one of the well known brands sold at a lot of big box stores has Chinese engines in some if not all models.
Familiarize yourself with the terms standby and prime. Most whole house units are not built for long continuous running. In fact running more than a specific number of hours within a period voids the warranty.
There’s at least one brand with a diesel converted to run on naturals gas that can be run for 2,000 hours before requiring maintenance. Typical life of the unit before rebuild is in excess of 30,000 hours.
Like anything else you get what to pay for. READ THE WARRANTY BEFORE YOU BUY. There are some gotchas out there.
Need to check how loud the unit is, too. Having the equivalent of a large riding mower running just outside your window gets obnoxious, and it’s a magnet for thieves, too. Noise cancelling in the exhaust would be a good thing to have, for your own comfort as well as safety.