It's just the usual. Nobody can say for sure what any of those settings do (I have an inkling but can't say for sure) and, when people post their configs, they vary wildly. IMO they vary wildly not because everyone's PC is different, but because people are just pissing into the wind -- they don't know what works. They throw a bunch of settings in, try it out and then say "hey that felt better". In reality it may be that they were just having a good round (or night). If you have one of those rounds, you may well convince yourself that it was the config helping. If you have a horrible round where nothing seems to work, then you'll probably say "shit config". I sometimes have those nights and I don't touch my config (much).
The only way to test this properly would be to go on a server and then methodically work through each setting in isolation repeating the same tests again and again and again, but that would be hugely boring and, worse still, you may end up with no conclusive results. Also, just because you hit better doesn't mean your gameplay will be better. You might end up behind the action (so although you can hit what you can see, the enemy might have already killed you by the time you see him!)