Since generator purchase is large spending, I suggest anyone interested in their product talk to Champion, go over the spec and discuss your need with them, and get a feel for how they treat their customer.
Personally, my impression was bad, I've never heard companies representative bluntly accusing customer "cheating" for warranty repair program. Even if customer lies to save their money, it's quite offensive to hear speaking so negatively of their customer base. I don't own Champion product, only making inquires to get clarification of its specification.
Price of Honda and Yamaha is double or more, but once you spend some time with their company rep, you'll be convinced spending more money in front to get the services you deserve.
Speaking of Costco, they're the worst of retailers in the market. Personally, I don't much respect for anyone who has nothing better than starting their career in cart-pulling, yet acts like such authority, speak so negatively of customer behind customers. They tout their return policy, but when customers want to use its advertised program, they have real nasty why of treating customers. One time I heard, I have no idea why their employee talking to me with friendly gesture but with such negative tone, a employee pointing to other customer, saying, "you see that guy, he returned a hose after he used for his purpose." Costco employees need to get their act together, realize their social status isn't all that demanding.