Just from a quick look and limited knowlege, since it is only 12" longer, I think if you measure you will find the distance from the rear of the truck to the axle is the same as a standard pickup (short or long, the distance is the same). If so, then no issue except the weight transfered to the front axle will be less due to the additional leverage (length between axles).
It is possible the extra space is behine the axle, however, since when loading material on the truck, the extra lenght would tend to put the material's cog behind the axle also.
Extra space when you have lots of extra capacity is always a nice thing. I see some custom doors being made into the sides to gain access under the camper winds. May not be water proof, but will be theft resistance.