A three year extended came with my deal as a promotion from Jayco. I don't know if I would have purchased it, but in my case it would have paid off. I had a few relatively minor issues that warranty covered during the first two years that would have cost me a little over a thousand dollars, but in my 4th year the Norcold died. That made the extended warranty good for me.
2006 GMC 2500HD CCSB 4x4 Duramax/Allison, Titan 52 gallon fuel tank, Prodigy Controller, B&W Companion Hitch
2010 Jayco Designer 35RLTS, Cummins/Onan RV QG 5500 EVAP, Progressive Industries EMS-PT50X, TST Systems 507 TPMS, RV Flex Armor Roof