"Swag" (hate that word... lol) works in your teen and young adult years when it's the most "socially acceptable." However in the long run, having style will trump swag.
Having style is "more reformed, more mature" so to speak... Swag is just essentially wearing all the clothes everyone else is wearing and acting the "cool way" at the time, which is ultimately kind of immature. Sheep-mentality...
Swag is hotter but style is sexy in a Calvin Klein classy sort of way. It depends what age group and type of girls you wanna attract. Your age group says 18-24 so 18-19 I'd go with swag 20+ with style but it all depends on what type of girls you like.
Obviously I prefer the second, but "swag" IS technically a style even if most people violently dislike it :P I mostly just don't care. I associate swag with douche bag, but if douche bag is the thing that bothers me, I'm not going to waste my time criticizing the clothes and not the behavior.
Swag is for the idiots who try to push swag on you because they think they look cool in their rap/hiphop video walking beside a car they shouldn't be able to afford with the crappy song they crapped out of their ass, or had had an ass write for them. when in fact they look uncredibly stupid style all the way. People who are actually cool would never say or do swag