Which do you hold more value on a boxer's resume if you were to make the comparison between 2 achievements involving beating everyone they've faced? Being unbeaten (Marciano, Floyd, Ward, Finito, Calzaghe) or avenging all defeats (Monzon, Lewis, Yuh, Bowe, Mitchell)? The idea of having a perfect record sounds nice but I also like when fighters rise to the occassion by not letting a loss affect them and is able to make adjustments to show that they can adapt while fighting adversity.
All things being equal, going unbeaten is obviously better. Not losing is indisputably better than losing.