I just bought the 4R two weeks ago, and it already has a crazy tire history. It came with Longtrail A/Ts, and a 14 year old spare. America's Tire Co. had the Longtrails under warranty, so I brought it in to have them inspected and give me a new spare tire. I bought a barely-used BFG tire for the new spare (they say it was very good, I need to check to see the specific model though).
So... Durring a Death Valley backroad break-in trip, I blew both rear Longtrail tires in the middle of nowhere. Pretty stupid, I know. The T4R performed incredibly well, overall. Just what I expected. Even then, I wanted to push it hard, discover it's limits in a harsh environment, but not give it undue stress. But I was planning on replacing the tires soon to get something better for off-road use, anyway. After the T4R limped back to civilization, I had them put on Pathfinder Sport tires, to give me better off-road performance. It fit my price range, and matched how I plan to use them.
They reinstalled the spare I had originally bought (underneath), and left me with one of the good front Longtrails for use as a spare. I'm getting it mounted, inflated, etc. onto a simple spare-tire quality rim.
So I'm never going off-roading in the desert without two spares (and 4 cans of Fix-A-Flat). I'm starting to think that it just makes more sense to load the #2 spare in the back of the car, and put a 50lb box of off-road supplies (tools, shovel, sand mats, tire inflator, etc.) on a cage, on top. It just seems easier that way. By the way, I will never buy anything but Fix-A-Flat brand. Nothing compares!