As a new player I can only speak to early game content and not endgame content, but FF XIV seems easier and less twitchy than other MMOs I've played.

WOW and SWTOR have a 1.5 second global cool down, so you need to know what ability you need to use next and be ready to hit it every 1.5 seconds, and that also includes taking the time to position yourself properly, checks for buffs/debuffs/DoTs/procs/etc.

ESO is even faster with a 1.0 second global cool down.

FF XIV has a 2.5 second global cool down. I hear at end game, you throw in a few abilities that don't count for global cool down occasionally and that positioning is more important in this game than others. But it doesn't seem very twitchy to me, at least early on.

I hope that helps!