I'd be interested to know what you're basing your figures on.
Fair enough - mostly testing and type training, so I did a little more research to refresh my mind:
To examples: Cessna 172S: Specified glide speed flaps up 68 KIAS, (POH page 3-5 & 3-14), "Landing without engine power, flaps up" 70 KIAS (page 3-3 & 3-5), "Takeoff: Normal climbout" (implied flaps up) Vy 75-85 KIAS, "Short field, flaps 10, speed at 50 feet" Vx 56 KIAS (POH page 4-5).
Grand Caravan: Specified "Maximum glide" speed flaps up 97 KIAS, (POH page 3-5 & 3-32), "Landing without engine power, flaps up" 100 KIAS (page 3-5), "Takeoff: Normal climbout" (flaps 20, up at 95) Vy 85-95 KIAS, "Best rate of climb" (flaps up) 104 KIAS, "Short field, flaps 20, speed at 50 feet" Vx 83 KIAS (POH page 4-26).
In both cases for those types, the power off landing speed flaps up is slightly faster than the best glide speed. I agree, that once flaps are extended, a slower speed is appropriate, but the airplane also slows down more quickly, and requires a more well timed flare. If you're practiced, that's fine.
But, for both of the types I have cites, Vx is significantly slower than Vy. If you have to accelerate power off from Vx to best glide, or the slightly faster "power off landing speed", there will be a large altitude trade required. The POH and training may be thin on reminding the pilot of this "avoid" condition, so awareness and practice are beneficial!