You can use the quetzal for a mass material gather. Or you could use its mass amounts of HP and Stamina as a battle bird. It may not have a huge attack stat but with its massive amount of HP when it's leveled up can be a formidable foe to even the alpha Rex. The best way for this would to use an empty platform saddle so you can dismount and stand on the saddle and the quetzal will not land and then regain its stamina.
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!