Better to ask about likely problems with any of the components, like the fridge or the AC or the furnace as these are the big ticket items to have repaired. I can see extending the warranty on something like the fridge if it is going to be used on a daily basis and less so if it will be used 30 days or less per year.
Expensive to repair and failure prone parts are where an extended warranty has paid off very well for me. Two examples are a HP printer that sold for $800 and the head replacements cost $60 each and I have had 8 replaced during the 3 years of the warranty. Second is a DLP HDTV that was prone to fan,CPU, and lamp failures and minimum service call and repair was in the vicinity of $500 or DIY still over $150 per item and over $500 for the CPU. In this case again the extended warranty taking the coverage from 1-year to 3 years paid off very well.
Now with a new LED LCD HDTV I did not bother with an extended warranty as the set itself has no moving parts and LED's are not likely to fail.
If a warranty only covers parts it is of far less value then if it includes both parts and labor.
NO Extended warranty on my RVs/TTs and other trailers either. If it breaks, I fix it. And, I fix it better than "factory build". Under warranty and it breaks, they only need to fix back to minimum build (if the item is covered). And, they only repair the broken item - not the damage it caused around it. re: Leaky window and it rotted out the lower wall and floor. They only fix the window. Nothing more. Besides this.... If the item broke or leaked the 1st time, then odds are it will break / leak again. For me, I keep the extended warranty money in my pocket and if needed, fix much better than factory. For example, removal all TT windows and re-seal using proper soft puddy method (instead of hard rubber - that leaks over time). Besides my much higher repair quality levels, I cannot soak money into something that is only used on weekends. And, only used 4 months of the year. For a car or truck that I use every day, then sure. Extended warranty compared against "times used" makes sence. But extended warranty on an thing that is only used on weekends and only 4 months a year???
If wondering, I've never lost the gamble with only 1 year base warranty on my many previous trailers either.
If you read the policy, I think you'll find that between "bumper to bumper" and the fine print of the policy there's gonna be a whole lotta holes that aren't covered, and a whole lotta "dancing and prancing" to get things fixed. Remember, the policy lists what's covered, everything else is on your nickel.