I've noticed in the achievements that there's one for each class for leveling 2 Heros of that class to 60. Is there any advantage to doing this is or is it simply for the achievement's sake?
With the advent of the new skills system that allows such easy respeccing, the only strict advantages are purely cosmetic ones:
- you can then have max levels of both male and female character models, and
- you get the achievement.
Other than that, any other differences would all be self set, i.e. attempting to level by only shooting Magic Missile at the darkness, etc.