This is all relative, and it all depends on how YOU drive. People who drive their cars to school/work daily really have no need for -3deg camber, while people that track their cars often need the camber for what they do. The reason that a tracked car's tires wear evenly with high camber settings is that you scrub a lot more tire off in corners (where the tire is contacting evenly under load) than you do in a straight line. If you run -3deg camber and drive like a grandma, you will wear the insides of your tires marginally more than the outsides.
Now, when people say its toe that kills tires and not camber, they are usually referring to the idiot who lowered his car and didnt get an alignment. What you have now is tires that are not only contacting the ground with just the inside edge, but are also contacting it with the wrong toe angle. Toe changes with camber on our cars! Combine the fact that you are scrubbing the shit out of your tires' inside edges due to bad toe settings with the fact that the outside edge hardly ever touches the ground because you drive like a pansy, and you have a very unhappy 240sx owner. This should all be common sense/9th grade geometry. I can't stress this enough: GET A FUCKING ALIGNMENT AND SHUT UP!
