Ive played about an hour using both a ps4 controller (with ds4windows) and keyboard/mouse, and this is what ive noticed so far.
The deadzone for controller sticks is terrible. There is a range, particularly with the right stick, where the panning speed of the camera stutters around, and isnt smooth at all. Ive never noticed this in other games so i dont know if its a game related issue or something about the software im using.
Secondly, the sensitivity floor is way too high. Ive set the sensitivity to its minimum both in game and with ds4windows and its still ridiculously high, especially while aiming down sights. At its absolute minimum, scoped in sensitivity is too high to reliably aim at mobs more than 30m away.
I really hope these issues arent ignored over the more widespread performance problems. From what ive seen there have been reports of controller input lag, but it doesnt seem like its related to what ive experienced.