So, /vp/. How did you decide on which flying type/flier to use?

I thought of using aerodactyl but from what I understand he's pretty late game. A friend told me Yvetal was awesome so that's a possibility.

Then I ran into bagon, and now we have a triangle of potentials. So who would you choose? Is it worth it training a pain in the ass pseudo anymore what with the ease of megas?