Well let's see, I've seen many flying fish, and they can fly (depending on the conditions) anywhere from a few inches to several 100 yards. But because they don't have legs or lungs, they pretty much have to land back in (or very close to) the water. I would have to believe a flying shark, also being a fish, would have to follow the same rules. A Pterodactyl on the other hand would have lungs, legs, claws, and the advantage of being able to attack from land or sky, plus the ability to carry you back to it's nest,rip you apart, and feed you to it's young while you're still alive...... I think I would be more afraid of the Pterodactyl.
I think a pterodactyl would be pretty terrifying to encounter. The only time I've ever "witnessed" humans encountering dinosaurs was in Jurassic Park and, well, that didn't turn out so well for most of the humans, did it?
A flying shark, on the other hand? I think it could be fairly amusing to encounter one. If I did, I would try to hide, but not be so hidden that I couldn't snap a quick photo with my smartphone to immediately upload to facebook and twitter. I mean, it's not every day a picture of a flying shark shows up on your facebook or twitter feed, am I right?