Its hard to answer this question without incorporating stereotypes, but generally I'd say southern guys are more rural, they might relate to each other in more traditional ways, maybe relying on straight relationships as a role model (tops and bottoms). In contrast, northern guys might have a tendency to be more urban, and relate to each other in their own self-defined ways. Generally speaking, I think southern guys tend to grow up a little more sheltered, and tend to be a little more closeted, and sometimes overcompensate for their homosexuality by being super masculine (cowboys and bikers) or super feminine (drag queens and impersonators). Lots of the guys I've met up north from cities sometimes have gay role models from an early age through family or teachers, and can be more "middle of the road".
Again, huge generalizations...of northerns (primarily northeastern cities) versus southerners (primarily Carolinas) from which I have first-hand experience in both.
