In the announcement video it bothered me how the weapon would be in the dead center when you aim down sights. It would feel and look much more natural if it was more towards the shoulder the weapon is shouldered on. I guess one might argue that with one eye closed, the weapon would feel centered, however a professional (I guess one can argue whether the basic soldier in PS is a pro, though) would fire with both eyes open.
Talking about shouldering. A feature where you could switch shoulder would be nice. APB for one has this feature and it feels weird in other games when you can't change to the other shoulder when approaching a corner that is on the "wrong side". This way you would increase the skill cap by allowing players to fire from the other shoulder near corners to minimize exposure.
Sorry, but I'm a real life gun hobbyist as well, so stuff like this sort of stick out to me