I'm leery of extended warranties, and I know that they are a huge profit margin for dealers. So a couple things if your set on getting one. Talk to the dealer service people about the company, they their response time is, approval, etc. If they don't like it they may tell you. Then negotiate on the price, hard. They're making money on the RV, they can give a lot on the warranty if they want.
Then shop around; do check out the Good Sam extended warranty, but call others. The plus to the one the dealer sells is they will usually do the work and then wait for the payment, but they won't for outside warranties - in that case you have to pay up front and then you have to wait. If the dealer won't wait on their own warranty then I'd run away.
Final thought, if you will honestly put the money away for warranty coverage and keep it, sort of self insuring, chances are you'll be money ahead in the long run.
