The pitching moment requirements of airfoils or combinations of airfoils for efficient flying wings do not have high maximum lift coefficients. Thus, flying wings require lower wing loadings for low speeds and thermalling applications. The flying wing configuration does well for slope soaring applications where most of the flying is done at lower coefficients of lift. There are two main advantages of flying wings. They have low parasitic drag and they have low wing bending if the mass is distributed similar to the lift distribution.
Swept back flying wings have much larger torsional loads than unswept wings. Because of differences in bending loads and torsional loads, swept back flying wing structures are different from unswept wings and the same structure will not work as well in both.
The design of swept back flying wings is more complex than for tailed configurations because every design decision has more interaction with other design decisions than for tailed configurations. In other words each one of the following affects all the others: CG, trim, airfoil, sweepback angle, twist, taper, lift distribution, and aspect ratio.
Bending along the length of a swept back wing panel results in a change in the aerodynamic twist as well. In swept back wings stiffness in both torsion and bending rather than strength are usually the controlling structural considerations.