I really enjoyed the new Ixion Fate and hoping we will see new fates in the future patchs like this one in stormblood areas and the old areas too because it makes the world a bit alive like what was happining with (Odin&Behemoth) and also it will make us enjoy the areas not like what happend in HW.
In terms of rewards i felt like 12 horns is not enough to make you get it as a mount i felt 20 is perfect and will make it more epic if you see someone with that mount or you on it.
Also if they did lvl70 fates again i hope they add a glamour rewards like what happend to the pvp new gears (lvl1 just for glams).