Internal frame, external frame ... neither ... both??? We have yet to decide. But what we DO know is that the NICE Frame is the first design we have come up with that provides a radically better carry than a well-fit and well-packed Mystery Ranch internal frame. A thoughtful redesign of the interface between the user and the load led to the idea of building in pre-programmed flex to an ultra stable platform in a manner that has produced a level of performance never thought possible with extremely heavy loads. The result is a comfortable and flexible frame system capable of controlling huge loads while remaining low-profile and unobtrusive with light loads. Five different styles of packbag completes the NICE Frame System, creating a true pack system that is capable of hauling any load you might encounter.