Onan or Generac? 😉👍
Generac is expensive, but worth it in my opinion. You don’t have to worry about turning anything on, but it kicks in automatically after 15 or 20 seconds. Peace of mind is worth a lot if you are on vacation or away from your home for a few days. Mine runs on propane and I figure that I can run full power in the house for at least a month. There have been many times where my house is the only lit one for a few days because of a brown out.
Go with a 1,800 rpm generator rather than a 3,600 rpm generator.
Pick one rated for prime use rather than emergency or backup.
Those can be run 24/7 until a maintenance interval such as an oil change is needed.
Some have run close to 40,000 hours before a rebuild. The number of zeros is correct.