I have the Nissan Security + Gold Extended Warranty!! It seems like a pretty good warranty only because it covers absolutly everything on the truck.The factory warranty is very limited! Also you get roadside assistance, car rentals, and towing are included with the warranty, which is nice for convienience. The downfall to this warranty is that it is expensive. It was $2500 for the 5yr/75000mi warranty. Fortunatly for me if I never use the warranty I get the whole $2500 back (Just a Warning: this may be dealer specific because the refund is not given through Nissan). The $2500 is refundable at anytime if I don't use the coverage, with no penalty. For me it is piece of mind to have it, but in the near future I may drop it only because I plan to do a lot of mods to my truck that I'm sure will void the extended warranty.
I've already argued with someone on nissanforums about this and how he said I was getting jipped because of the interest I would be paying on the warranty and how much of a repair I would have to make it worth it. I like to research things and I knew about all of this going in to buy my truck! For me it is just a piece of mind to know that the truck is covered. Hope this helps!!