Calista's passive is wrong approach to create mechanically demanding champion
Riot decided to make really high skill champion and it's fine. But canceling autoattack to dash just seems clunky, uncomfortable.
It's like Dark Souls was hard not because the enemies are hard, but because controlling your hero is awkward and clunky as hell. Imo that's jut bad design and games with bad controlling simply aren't fun to play. Maybe people will love it, but I already know that I'm going to hate playing Calista, because of that passive.