Southpaws obviously favor the cross for aformentioned reasons, but as for a general question of what is the style of southpaws, well it used to be that southpaws were known purely as boxers who stayed away and tried to time their cross, but as there have been more and more southpaws coming onto the seen we have seen everything.

Pacquiao, Wright, Dawson, Calzaghe, RIgondeaux, Casamayor, Juan Manuel Lopez, Judah, Whitaker all have unique styles. If anything being a modern day southpaw means that you don't really fight like anyone else. There are almost as many top end Southpaws as there are orthodox these days.