I think what would help everyone the most, is just to have the ability to toggle it on or off. If you have the option to be warned or not about a mob that will aggro you, it pleases both sides of the argument. I don't see how having a toggle feature is that big of an issue. I personally, like the surprise of sometimes not going, that is really exciting for me. Though others that don't like that should be able to have the ability do know, before they get in aggro distance.