Flying types are decent. I always have one in-game to Fly around places which is very useful. I also have a few favorite Pokemon that can fly like Zapdos, Aerodactyl, Articuno, Dragonite, and Salamence.
As for battling competitively, I usually have one of them at most. Drawback of having flying types is being weak to Stealth Rock. Losing 25% (or 50% from double weakness) of your health from just switching in can make flying Pokemon much easier to get OHKO'd. >_< I don't carry Rapid Spinners either. I don't have room for them in my team and people usually have Ghost Pokemon to block the move anyway.