First Result When flying in the air the players arms and legs movement animation is too slow, even when sprinting. It's as if they're walking on soul sand.
Second Result Now fly up, fall down a little, then fly forward. Observe that the player's arms and legs move faster.

The player is suppose to move fast in both situations because the player can also sprint and has no limitations when flying in the air.
http://minecraft.gamepedia.com/Flying