Everyone's situation, risk tolerance and financial status will be different with regards to a service contract or extended warranty. As a weekender with a simple budget coach that I only use maybe 50 nights a year the benefit didn't justify the cost to me. Anything that fails I have the time to save for the material cost and can probably effect the repairs in the driveway saving on shop labor.
If I was full timing, heavily dependent on every system in the rig working all the time and living off my retirement income I would give much greater consideration towards entering into a contract.