Speed alterations either way really can make a video more interesting.
I really like speeding up footage when I fly a good distance and it's interesting all the way, but too boring leaving it at normal speed for say a minute.
After starting towards a point, I might speed up for a while, if passing something interesting, slow it down to normal again for a bit, then ramp up again until I get to near the farthest point of interest.
So too slowing down video at certain points to capture something very fleeting, even accidentally captured like this . . .