Those situations where you shoot an entire clip into someone and the person kills you:
This is lag on your end. If you watch the killcam (which is the host's perspective), you will often see that you didn't shoot any bullets. This means that the player who killed you has a better connection to the host than you do. In the forums, I see this often mistaken for "lag compensation" and some believe that a slower connection is being somehow rewarded. This is not the case; it doesn't matter how good your download connection is - you will always be bottlenecked by the host's upload speed. If you see youself not shooting a single shot in the killcam, you're lagging worse than the person who killed you. Not the reverse. You are indeed the one with a bad connection in this case.
Those situations where you are being shot and die immediately after turning a corner:
This is lag compensation at work. Because of different internet speeds and latencies, different players will have differing views on where other players are on the screen. So while a lagging player may see a player as not having turned a corner, the player may have already turned the corner in his own screen. Without lag compensation, the lagging player would not be able to hit the turning player because on the host's screen he is not there. But with lag compensation, the lagging player can register hits even with lag. <-- THIS IS KEY
Lag compensation takes the average latency of the lobby. And artificially brings people (like the host) up to said average. It gets more complicated than that but that is the gist.
Conclusion:
Lag is the issue with this game, not lag compensation. Yes - this game has lag compensation, but without it, it would be unplayable (especially since the average upload speed in the US hovers around 0.7 mbps). There is the issue of lag compensation hurting better connected players, but it's not that big of an issue in my opinion. Just play with people with good connections to bring the average latency down and minimize the lag compensation.
Edit: Let me add that when I say Lag is the issue with this game I simply mean that it will ALWAYS be an issue because the host's connection determines the amount of lag experienced.
If for example you had dedicated servers. With a consistant speed. Then Lag Compensation even in its current form would be almost unoticeable. It is visible sometimes currently because I am pretty sure a majority of you at home share your connection with other people. Children, roomates, family. etc. Therefore the connection is not CONSISTANT if you are host.
Whatever I want to rant more but if this isn't clear enough then keep making QQ posts. I am just going to immediately block and ignore anyone who cries, or makes a post about lag compensation.