The Moogle Treasure Trove event has started...

[Vahlnir]

Got my pegasus mount and minion. Do I care enough to go for a white lanner too?

In the time it would take you to farm that many tomes, you could have probably gotten the full set of Heavensward lanners from random drops.

[TheMightyMollusk]

In the time it would take you to farm that many tomes, you could have probably gotten the full set of Heavensward lanners from random drops.

25 runs through Syrcus Tower, versus a random amount of time fighting six EX bosses (I already have Ravana's bird)? Including the time to find groups willing to do it, repeatedly in the case of people dropping when they get bored, or get their own? Or doing the same fight 99 times if RNG hates me today? Even assuming they can actually clear each fight on the first pull? And leaving aside that I've only done EX Bismark and Ravana, so I'd have to learn the fights for the others as well?

[Iscah]

25 runs through Syrcus Tower, versus a random amount of time fighting six EX bosses (I already have Ravana's bird)? Including the time to find groups willing to do it, repeatedly in the case of people dropping when they get bored, or get their own? Or doing the same fight 99 times if RNG hates me today? Even assuming they can actually clear each fight on the first pull? And leaving aside that I've only done EX Bismark and Ravana, so I'd have to learn the fights for the others as well?

Bismarck and Ravana are the only birds available from the event anyway.

I've joined Bismarck WT parties a few times, and got the whistle very quickly. If most of the party already have the mount and are there for the WT stamp, you're going to have a good chance of winning the whistle if it drops.

I don't know if it was just good luck, but I got Ravana's whistle very quickly as well.