Your choice. Its personal. I love mine and have other cars so I use it when I want and don't let gas get to me. 
But also remember, you will take a bath selling it. Probably loose $10k. Not that your payments, gas wouldn't go down, or that you won't loose that later when you resell, but you will be getting another ding when you get the new truck, so in the long run, its one more depreciation you'll need to cover. 10 years from now, you'll be out the extra cash. That amount covers a lot of gas and extra payments.
But also remember, you will take a bath selling it. Probably loose $10k. Not that your payments, gas wouldn't go down, or that you won't loose that later when you resell, but you will be getting another ding when you get the new truck, so in the long run, its one more depreciation you'll need to cover. 10 years from now, you'll be out the extra cash. That amount covers a lot of gas and extra payments.