I use face #3 for my male Au Ra. The horns are kind of weird but the face is nice, and that was more important.
People rarely use the 'old' face options for any of the races. In a pure RP, playing around sort of game it would be different - if I could create a character and instantly have access to everything just to play dress-ups with them, I'd certainly try out some of those characters. As it is, I've played around with them in the character creator and made face designs that work nicely, but I wouldn't want to put the countless hours into leveling them through a story that's clearly written with a younger protagonist in mind.
I don't think they could give the option for horns instead of limbal rings, because it's a different type of setting - two options that toggle on or off independently, associated with a colour selection, instead of "pick one of four" for the horns/tails. Every race seems to have one setting that uses this bit of data, but the actual things are different: usually it's race-specific tattoos, though Wildwood Elezen get the choice of coloured earrings instead.
An interesting alternative to limbal rings could have been colour customisation on the horns, similar to Yugiri and Mide having unique colours! Though I think the limbal rings are a bit more necessary for Xaela males so their eyes stand out more.
I still think it's weird that only male Xaela have the black eyes. Either do it for all males, or (preferably) all Xaela, but not just one gender of one clan.
I assume there'd be an ear-length slider similar to Elezen and Lalafell.
There are definitely at least two kinds of ear designs for the characters in the preview video - the blonde girl's ears have more fur at the base and are wider towards the tip, and are quite a bit taller compared to the size of her head.
The pink- and white-haired girls have the same ears, and those seem to be different lengths too. It's a bit hard to judge when they're not standing at the same distance from the camera, but I think the pink girl's ears are a little bit longer.
