as i said i have the chrome ones, and my car initially didn't have a passenger side mirror so i was used to not using that anyway. After getting out of another car your initial instinct is to look to the corner of the window, but once you get past that it works quite well. the black ones would work slightly better as the standoff is like 1-2cm longer or something like that, where with the height of the chrome ones the very bottom of hte passenger side mirror is blocked by the windscreen wiper, but as i said i'm used to not having a mirror there
basically once you adjust them there is no need to ever do so, as they show quite a large area, so it would show the correct area for basically everyone. the only annoying part is if an interesting car (or chick..) drives past the other direction its harder to check it out once its gone past as the reflection is aimed basically further behind the car, well thats how i have it so i can see my car in it as a reference, and see the blind spot.
and yes they look cool, and it definately makes people look twice, can't wait to flares and spoiler is installed

i always thought there must of been some functional reason why they were installed on the fenders for the jap market, like they work better etc, just they were deemed to much of a hazard in australia, but researching it more its just about getting into the lower tax bracket again lol