I recently did a flight test of my Lancair 235 testing TAS, true air
speed, vs. the reflex angle of the flaps, i.e. angle of the flaps above
the wing surface. The test was flown at 1535 lb, 11,000' density
altitude, full-throttle, leaned for max rpm.

+8 deg. - 196.2mph; +6 deg. - 199.7mph; +4 deg. - 196.2mph

+2 deg. - 189.3mph.

The test demonstrated that careful adjustment of the flap reflex angle
on Lancair or other aircraft so-equipped can result in higher TAS. The
reflex angle is sensitive to IAS and weight. As IAS decreases or weight
increases, L/D increases with less reflex, more camber and lower body
angle. An additional positive effect is that at the lower body angle,
vision over the nose is enhanced!