The Cummins/Onan generators are mostly used as RV generators and are only available AFAIK up to around 12.5 KW, but they are possibly the best stand by generator going IMO. If you need something bigger, the Kohlers are the best rated, though a bit more expensive than the Generacs. Where the real cost usually comes in is the options that are available - most of which are part of the Automatic Transfer Switch (ATS) . Automatic excercising, battery charging, block heaters, low oil alarms, fire alarms connected to your alarm system, etc. are all good options to have but can get expensive..
