Hi rider,

Pitch stability on flying wings is obtained either by using a reflex-cambered airfoil (e.g. E186) on plank wings, or by using sweep+washout on swept-back wings.
Both solutions decrease max lift by some amount.
Moreover on plank wings, positive Cm0 airfoils usually need large cords (high Reynolds) and thus low aspect ratio, thus increasing induced drag.
Last but not least, longitudinal stability on a flying wings is just one issue. Lateral control can causes some (or a lot of) trouble, too

Thus there there are cons to flyingwing performances, especially at high lift coefficients (i.e. less detrimental to high speed designs). However there are pros, too, as without a fuse you decrease parasite drag.

Manu.