The Quetzal can be good for carrying goods a long distance, what I do on my single player game is make a platform and bring doedicurus(reduce weight by 1/4) stone mining dinos and a few ankies(metal weight by 1/4)to store my metal ores onto and travel back to base with a large amount of resources, i bring a argy to carry my ankie but make trips to unload at my quetzal till he is full, I can pull x5 more resources this way than carrying an akie and flying with just my argy.