I can tell you only from my own experience that campers are something I have seen only less of after the change from MW2 to Black Ops.
And regarding the sound: Loud dose not equal good in anyway, its the "positioning locator" in that regard its much more precise than in the previous games, it's almost as good as in Counter Strike and Battlefield games, what I mean by this is I can almost aim with my eyes closed if the map was big and open and an enemy was running around there. I hope you know what I am talking about now.
Regarding the stopping power and line of sight. Let me try to explain it better.
In a more open map which are seen in MW2 you would have more time to shoot at enemys because you would see them for longer periods of time, there would not be so many guys that got away if you were to open fire, because its open and you have more time to put damage on them. now add in stopping power aswell. What we end up if is spot = no escape as long as the shooter can aim somewhat, and lets face it everyone can aim after 1 hour of playing somehwhat...
So even people who are not considered good by themselves or others will have a good chance of killing by just aiming in the direction of the opponents and they will have time to keep the fire up for longer periods of time because the maps allow it.
Now in black ops the maps are tighter, which means there is less time to kill after first spot, and no stopping power either which means sometimes you will have to use the entire magazine and then some to just kill one person should a cat and mouse ensue.
What this also means is that it will allow the person who got spotted to come up with a response and counter the attack, this is much more true in black ops than in MW2, and this also will come down to who is better aswell, if the spotted guy is really good he will kill the one who saw him even if he got spotted first more often than not.
And if you look at counter strike for example this is even more true, its not just about who sees who first its also about how to counter the attacks, what plan and diversion you come up with, set yourself into the mind of the opponent and do the unexpected, use tactic and planning coupled with good aiming and fast reflexes rather than just shooting at things that you see moving.
"any noob that gets caught with his pants down has a better chance of surviving"
Yes but if the guy that is shooting at him fails to kill him even though he saw him first and then dies himself, well... then we have a case of not just one noob but two. A good player should win if he spots first against a noob, because he will have shot him, done more damage and be ready to kill him of with either a flash or stick or whatever, because when you get shot, you first look whos shootinng at you or try to get away, while the other guy is only thinking about how to finish the job, if he fails that, then hes no better than the guy he was shooting at in the first place.