Peacocks with their giant tail feathers are my favorite example. They make flying really difficult, but they make attracting female mates much easier. The reproduction need wins.

I don't know if I would consider it especially difficult for them. It is obviously not convenient but when I had peacocks they would still fly way up in some tall pine trees to roost even with a full tail without too much trouble. That said these were domestic peacocks so they didn't have to fly very far at all for everything they ever wanted, wild peacocks might have to go farther.

And that, my friends, is why I bought a Pontiac...