I agree inferno. Lock-ons and auto-cover makes the game far too easy, and done poorly, can almost make you feel like you're just watching a pre-rendered movie that changes a little when you push buttons. It can really make a player feel removed and distant from the action. I've seen a lot of games lately where you come up to certain points, for example, you must jump from one roof top to another. Instead of you actually running and jumping on your own, you walk to a spot and push a button. Another example would be there's a pre-determined fight sequence, and to win, you have to watch the screen, and push a button when it tells you to. That's really no fun to me. It's not very challenging, and never turns out differently. You either push the button, or you don't. There's no other options or possible outcomes.

It's not a shooter, but one of my favorite 3rd person games ever is Zelda, which is saying a lot for a person who really doesn't like fantasy or 3rd person games. I've been playing it since the original one came out when I was a kid! <3 But I think the style of it is relevant to the topic. It's one of those games that has intuitive controls, but is challenging, and makes the player think to overcome obstacles and challenges. It also turns out differently when you perform differently, and has a very dynamic system of event branching. There's always more that one way to solve a puzzle or problem, and the method you use can create an alternative outcome. I think emulating such a system of progression through your game could make it a real hit!