All the vehicles I had bought with extended warranty (GM and Ram) I just used the warranty sold by the dealer. No deductibles and no questions asked. Never had any issues with a thing. I did not opt for the extended warranty on my 3500 as it was over 4000$ and only brought the chassis/drivetrain up to 100,000km, which in my case might buy me a year and a half. My engine/trans has factory to 160,000km.
You have to do a risk assessment on things. Is that extra cost and possibly restrictions worth it? What or how much of a repair are you going to still have to cover? What are the usual items that fail after warranty and can you fix them yourself for cheaper?
I figured that I would have a good idea of how my chassis/drivetrain was behaving in the first 60,000km. There is usually an emissions warranty that is separate (if not covered and I have an issue, delete will be happening), the big ticket items on my truck are the engine and transmission but the Cummins gets 160K as does the AS69RC.