My group farmed Garuda for about 2 hours the other night, we got 3 Xanthos and a Nightmare.
Since the patch in total we've gotten;
4 from Garuda (not counting the Nightmare)
2 from Titan
1 from Ifrit
1 from Shiva
and we've just been running an hour or two a night after raid is done.
The drop rate has been good enough to us for us all to aim for Kirin.