Two questions here...
- Should you buy an extended warranty?
- If so, which one?
Financially any extended warranty (repair insurance) is a gamble, betting on the possibility of high future repair costs. Like any insurance, you only come out ahead if you have more than average repair needs. Sales people will try to convince you that major repairs are highly likely, scaring you into buying their product.
If you decide you want a repair insurance policy, shop around. Odds are you can get more coverage for less cost from some source other than the dealer. They get a substantial commission for selling those policies. Try a broker such as Wholesale Warranties, or Good Sam or America's RV Warranties.