I do not prefer Black as, for example at the fifth and last round of a five round tournament if I have had 2 whites and 2 blacks--much rather be paired with the white pieces.
However those who want to aspire to say expert or master should try and have a repertoire for Black which gives good winning chances. Even in correspondence chess where many play for the draw with Black--I think it is ok to play for the win....
I prefer black. I'm more prepared as black in the openings.