Originally Posted by NeverSatisfied 
The thing that confuses me is how they say setting a POSITIVE number for EV comp actually results in UNDER-exposure, and vice versa.
It seems to me that it basically offsets the ZERO point, but obviously it is still at the center, so if you set EV+1, and it was zeroed in to begin with, it will show -1, then you adjust the exposure (either ISO, TV or AV) to get back to zero point, which in reality, it will be EV +1.
It does make sense how it works, but I am not sure how this could be better than consciously being aware that you are shooting EV+1... and like someone mentioned, if you do set this thing other than zeroed and forget to set it back, i guess it could be trouble...