Quetzals are very cool mounts.
I have used quetzals to kill alpha rex's (Level some hp, rest melee damage)
To haul stuff across the map (Level some stam, rest weight)
As a portable crafting station (grill on platform for prime, pestal/bench for narcotics).
Depending on server setting in pvp it can be used to:
Drop medium size dinos on enemy bases
Arial assault machine (Turrets on the platform, level loads of HP)
Bullet soakers with high armor saddles (level HP)
Mobile spawn points (Beds built on platform inside metal structure)
Pickup medium/medium large dinos to take home for taming
They are really great companions to have in such a game! congrats on your new tame!