Beruka - I didn't use her at all in my first run of Conquest or Revelation, but I've made a point to use her in most of my non-PMU playthroughs since. I've found that I really like all Beruka's supports that I've seen, especially with Silas, Odin, Kaze, Oboro and Charlotte. As a unit, I find her to be pretty good. A Wyvern Lord with high Skill to mitigate the iffy accuracy of axes is really nice, although I've ended up reclassing her to Master Ninja twice (once by choice, the second time by PMU), and I find she functions pretty well in that class, her high Skill fitting in rather nicely and her Strength somewhat helping the otherwise low damage output.
Caeldori - To be honest, I haven't really used her (I haven't used most of the child characters in Fates), but what I have seen of her annoys me. I never really liked Cordelia, and Caeldori takes what I don't like about her up to eleven. It might be too early to make any proper decisions, but as things stand I'm not a fan.