There is a gunsight and yes, glass cockpit is an advantage once you learn to use it.
Explain this gunsight because I have never seen a gunsight in F3 mode. You also haven't answered my question about actually even trying to see if you could do better with F3 than without. I feel that until you do at least try it out, it is not right for you to say that these guys are actually using an advantage. Back when I first started out in H2H and not understanding a lot of the unwritten rules I tried to fight in F3 and foudn this to be very difficult to actually fight. However I did find it to be helpful in finding the fight in the beginning. The only advantage I can see F3 giving is allowing you to make an attack plan since it allows you to see the area around you and not to have to create the mental image. This does not bother me if some use this. I do not anymore since I have become more able to create that mental image but I did in the beginning as I was learning.
I really think that a lot of these situations that you believe someone is using the F3 as tool to get better shots off is probably more luck on the part of the shooter since a lot of these newer guys spray and pray more than most. Perception is usually the leading cause of mislead accusations.
None of this intended to insult or be demeaning in anyway. Just one man's opinion and experience (not that i have a lot of experience in game but enough to have an opinion).
additiional note since Widewing entered his in while I was typing:
Widewing you are a very efficient killer anyway. I was simply trying to say that most likely those that do kill in F3 mode most likely can make kills in cockpit as well and probably just as good as the kills made in F3 mode. I have tried doing this in offline before and could not even come close using F3 as I could in cockpit not even when I first started playing. I have no doubt that there those people that can make kills in F3 mode but I would venture to say it takes every bit as much practice to that as it does to learn how to do it in cockpit. F3's biggest advantage is in the SA department more so than making impossible shots (IMHO). I know you said that can kill very efficiently in F3 mode but would you say that it is easier in F3 mode than in cockpit. Would actually like to know since this is coming from someone respected in community and also has used F3 for sneaking peak and killing. Thanks Widewing