i made my 1500-mile trip last weekend. I learned that, whatever else the bronco ii may be, a highway cruiser it ain't.
The drive over (fairmont, mn to detroit, i-90->i-35->us-18->us-218->i-380->i-80->i-94) was into a ferocious wind out of the southeast. The truck wandered quite a bit in the gusty winds, and gas mileage sucked: I got 17 mpg out of the first tank, and 19 mpg out of the second. The last tank, which was all driving after the wind had died down, was 23 mpg.
There was one spot where it was squirrelly enough that i was frankly scared that i might not be able to keep it going straight, the winds were so bad.
The ride was also quite rough. My roommate, who works nights, tried to sleep in the passenger seat, but wasn't able to sleep well at all.
I'm sure it's a great off-road vehicle, but the very things that make it so work against it on the highway.