Just because his mpg are different than some posted doesnt mean something is wrong with the trailer. Some drivers might have a heavier foot than others. BTW, he did mention mountain passes. Dont go buy a ford. I swear Lincster is ford saleman and does not want to admit it.
I got horrible mpg with my 05 duramax/ allison pulling a 30' 12 k 5th wheel. Everyone I talked to said something was wrong with my truck. I do believe with as many trucks that are produced something is bound to go wrong with a handful. Weather it be tranny issues or motor issue or programming issues. But to have an issue with 2 truck, without ever having your trailer looked out it will be hard to know for sure.
Get trailer with more room. You can never have enough room.