Increase feather drops for bosses across the board except for Sidi/TG/Galla IMO. Dragons, the bigger DF bosses, and other mobs that require a raid or at least a few well-coordinated groups should all be worth much more in terms of feathers. Sidi and the other epic dungeons, as well as the smaller bosses in places like Llyn Barfog are fine as they are because at least with them you have a lot of bosses to kill, whereas on a dragon raid the only thing that drops feathers is the dragon.