Jumpslashes are actually pretty effective in a fight sometimes, you are just a wee bit faster when you jump instead of walking to an opponent. It catches some off guard. Just be prepared to block cause theres a pretty big chance you'll miss. Also against horsemen it works pretty well nowadays when you sidejump just outside their lance arc, you just need a long enough weapon to still hit them in the face.
Tbh, i had easier time jumpstabbing horseriders before the nerf
Now i somewhat take it as granted and underestimate, i can kill most of the noob cav, but when i try to pull this off on some leed or whatnot, i am done...
I also love to fall down on enemies with hammer releasing shortly before i land