I've seen a lot people complain about how easy the game was. Even when I watch YouTube videos I see that everybody is playing on auto aim. I've been playing on free aim since RDR. It's way more fun as you feel like you're earning the kills, and it provides a challenge that automatically locking on to your target can't provide.
To those of you playing on auto aim, you should give free aim a shot on your second play through. It will upgrade the experience entirely.