There's a reason they're so goddamned hard to tame; they're a gamechanger. Even if you don't have a platform saddle they are extremely useful. They have a massive amount of stamina so they can fly for extremely long periods of time, their carry weight is comparable to some of the bigger land creatures like a diplo, and they can carry absolutely massive creatures through the air. It can make setting up bases in newer areas like the snow biome much easier. Personally I use it to make trips to some metal deposits in the tundra so I can get bulk amounts at once without either encumbering my flyer or bringing a clusterflock to disperse the metal. Once you have it, take very good care of it.
Quetzals, one of the best dinos. Quetzals can easily be tamed with a buddy, all you need is a flying dino that can pick up people or has a multi-seat saddle. Load up with the appropriate tranq arrows, narcotics, food and set off across the map to find one. Low levels are brilliant for beginners as they can serve as brilliant carriers due to their high base weight stat. Higher levels however mainly are used as "Battle Quetzals", alongside the high stats it will receive from being tamed, pumping health and melee damage is the way to go. With that being said you'll be able to tank base defences such as PSX and Auto Turrets, aswell as kill dangerous dinos with ease. Maybe either of those don't tickle your fancy, then hey, make a "Party Quetzal"! Strap on some chairs, tables, food and lots more onto the Quetzal's Platform Saddle and hover in the air as you dance to Darude Sandstorm being blasted through someone's mic in game chat. If you can get a quetzal, do consider as they are brilliant!
When you tame your first quetzal, you should make it into a quetz trapper... if you are wanting more... if you don't know what a quetz trap is, go to YouTube! If you can tame a low level one to start! Being able to tame as many quetzals as you want with the trap, is RIDICULOUS!