We bought a 2011 Explorer in the same way.
It was a rental with 20,000 miles.
It was $20,000 instead of $35,000 (at the time), so that is what it is.
Issues.... none really. Vehicles looks and feels brand new. My daughter and wife like that it sync's tho their electrical bs. My son and I call it "The marshmallow" due to it's road handling feel (or lack of, we are kinda snobbish regarding these things).
That tiny Ecoboost engine is weird for me due to my affinity for big blocks. Sure it's got power, I'm just not used to revving the engine to 6200 rpms every time I pull onto a highway.
I rent a lot of cars for business. At every place I've rented a car, it's normally 5-6 times more money to rent a Ford Explorer. Would I buy a Chevy Cobalt or any of those other cheap subcompacts from a rental place? f*** no. but an Explorer? yeah no problem. I see the people that rent them.....
So no real issues with buying it..... I bought it because my wife likes doodads in a car. My personal point of view for you? take that $20,000 and sink it into your 76 F100..... live a long happy life.