With controller, you'll be a lot slower in combat than your k+m companions (switching weapons, taking potions etc). Works for me, since I hang back a lot and kite, but it's something to keep in mind.

Overall controls for gamepad work great for me. If you start the game from Steam Big Picture mode, you can even enter text for map markers / signs / ... . But personally, I usually prefer to do that via keyboard.

There's a bug that might not have been fixed yet where the game switches the trigger buttons. For me it helps to connect the controller AFTER starting the game.