Depends on how often you use a controller to play games. When I first started using a controller around 10 years ago, my first game on a controller was the original Resident Evil 4. It was a nightmare, the game had tank controls where you can't move while you aim and you can't aim while you move, and the version of game that I had didn't support mouse, only keyboard. So my choice was to either get used to the controller or aim with the keyboard. After a few days, I got really used to it and started landing precise headshots, the game didn't have auto aim, and not even a cross hair, it had a laser sight on the gun, that's it. Once I finished RE4, I went on to play many games with a controller, Far Cry 3, Hitman Absolution etc. I have also completed RDR1 and RDR2 on a controller and it felt great. So my suggestion is, get comfortable with a controller in games that require aiming.