Is it just me, or does it seem like the Dynasty kicks are slower than Heralds'? I mean, it seems that it should be the other way around because the Dynasty is supposed to be the swiftest and most "elegant", right? Dunno. :3
Imo, Dynasty is more of a graceful class while Heralds are practical. So in the former's kicks you may notice more of style/flair. They will kick you multiple times on the same spot, spin around, canonball and whatnot. Heralds on the other hand are like kick to head-kick to the chest-swipe out your feet and you are down.
In game however, a lot of it comes down to which special abilities you are using. Some kick sequences take a bit longer to complete on account of their complexity. Personally I have not noticed that much of a difference between the two. But it's probably because of the ability cards I'm using xD