This is a subject that comes up regularly and has no single answer that fits everyone. My random thoughts listed below are simply intended to provoke your thoughts.
The cost is quite high initially.
You need to know the terms and conditions at least as well as the people who write the policies. Be very aware of what is covered and what is excluded. The exclusions can be costly.
If you are including the warranty in a financing package you will pay significantly more for the warranty than the initial cost, maybe double depending on the term of your loan, and be paying for it long after it has expired.
If you are writing a check for the warranty up front you would be better served by writing that check to yourself and establishing a maintenance fund and adding to it as you see fit. In over 90% of the cases I have seen you will have money left when the coach goes down the road to another owner.
If peace of mind is a consideration it could be achieved by establishing a line of credit, which is nothing but a pre-approved loan that you haven't used yet, with your lending institution to cover the possibility of a major repair like an engine or transmission loss. This generally costs nothing but the time and effort to set it up and only matters when you access it. Credit unions are probably better sources of these types of things today for individuals since banks are rather impersonal any more.
In the maintenance fund or line of credit scenarios there are no hassles over what is or isn't covered. No deductibles, no approvals for services or repairs required and complete peace of mind.
Or, if we were all wealthy beyond our dreams, we could just pay the bills as needed.
Enough of this nonsense, let's go somewhere and have fun.