I turned true iron sights off at around level 4. I just found that the aiming mechanism on most guns just obstructed your view of what you were supposed to be shooting at. Some guns were fine, but most just resulted in me aiming in the direction of the enemy and firing blindly behind the barrel of my gun, just hoping that the gun was at the right height to hit the target. I'm glad that it was included as a new feature, but it just wasn't for me. :shrug:
Thats why I typically dont use energy weapons, most of them dont even have ironsights, and the ones that do some of them you cant even aim with due to all the vacuum tubes restricting your view. Not to mention I typically dont put much skill into the energy weapon skill in my play throughs, I focus mostly on survival, repair, science, and guns.