I buy new. It is just a personal preference. I like the idea that nobody has ever driven that truck but me. I realize I am paying for that.
With the economy in the state it is in, trucks are not losing their value like they once were, but your dollar is. Financing at 0% is a great tool because you are locking in the value of your dollar.
I only like financing when you can get 0% otherwise I would pay cash. I would definitely buy new now over used because people are not trading in trucks with 20k miles and when dealers get them they are not selling them at a big discount when compared to new. Also, used do not qualify for 0%, so when you add in the interest you must pay on a used truck, you are better off buying new. Around here, trucks with 100kmi are still in the 18k-25k price range.
Now if you are willing, I have heard that in areas out west you can find great deals on lightly used trucks. I know a guy here in WV that flew to Idaho to buy his truck and drove it back here. Even with the added travel expense he saved thousands over what dealers here were charging for comparable trucks.