Controller on PC since I found out you could use one. Xbox Elite controller (so expensive but so nice!)
the 6 different full crossbars are sufficient for everything I do, though i'll admit I've popped sprint by accident a few times when I forgot whether it was Lt>rt or RT>LT.
I don't even know if I could play with keyboard at this point.
I also have extra hotbars up on the sides of the screen just for keeping track of procs and summoning particular mounts/minions.
I like being able to walk places just by gently moving the stick instead of toggling it with keys.