Someone I know bought a Terrastar on Ebay. He thought it was the best all around platform for his overland vehicle. He picked it up in, if I am not much mistaken, Missouri, and well before he was halfway home to Colorado he called his wife to tell her that he hated the thing, horrible ride, and it just did not fit like he thought it would. Among other things he said it road really horribly.
What other trucks are you considering? Personally I was impressed with the F650 used in the Eco-Roamer. The major draw back there was that it started out life as a 2wd and had to have the t-case and front axle added. Never the less he took the potash up and out via the Shaffer switchbacks, and it did really well in that, so that says something I guess. I am not saying that this is the truck for you either, only suggesting that you might go out and drive a few of them before you buy, and perhaps get one of them to let you take a truck for a weekend before you buy etc.
Sorry your truck is not what you hoped. It seemed a curious choice, but I was optimistic. Who knows, perhaps they can work it out for you at the shop!
"Do you know what a soldier is, young man? He's the chap who makes it possible for civilized folk to despise war." -Allan Massie