I am heading down to the dealership this Friday and finally will get to order the Duramax now that the LLY is available. I am set on just about everything I want or need but still have some indecision concerning the SB vs LB. We will be getting a 2500 CC 4x4. We pull a 31 ft trailer and I like the idea of having the 34 gallon fuel tank as opposed to the 26 gallon one on the SB. This truck will be a daily driver, mostly highway. Any pros or cons for either box? Tough to navigate?