I'd like to add that apart from cast times hampering mobility and oGCD usage, some people just don't like the way they *feel.* I would rather have instant casts than cast times even if I'm standing totally still and using no oGCDs, simply because instant casts feel quicker and more responsive to me. There are already enough jobs with cast times that I feel the game ought to have at least one cast-free rDPS for sake of fun and playstyle diversity.