I do think the arrow keys make it a little easier to aim, would some drag to aim moving left/right and releasing the mouse to go down give a bit more reasonable feeling of the experience?
I'm just aware that when you're playing you don't feel like you're moving in very fixed increments left/right when aiming, which using the keyboard seems to produce as an experience.
You don't actually move in fixed increments with the arrow keys. You start moving, initially at a slow speed then faster as you keep it pressed up to a certain maximum speed.
You'll only get the same results if you have exactly the same timing every time you tap the key.
That said, I've been prioritizing the touchscreen controls because that's where a majority of traffic comes from. I don't want to neglect desktop users entirely though!
I'm just aware that when you're playing you don't feel like you're moving in very fixed increments left/right when aiming, which using the keyboard seems to produce as an experience.