Ahh just my opinion man. Tecnical wise whats considered to be metal is definitely better. OTOH Punk is a lot more diverse in it's forms. Ska, Emo, hardcore, straight edge, poppy, happy etc etc etc.. If I was starting a band any band and was looking for someone who is more skilled at the guitar and had to choose between a punk and a metal guitarist I'd choose Metal. Music wise, I listen to Punk more because of it's content and aggression. I do listen to a lot of Metal also. Pantera, Opeth, Megadeth (pre symphony)
Old Old Metallica, CoC and lots others.

I didn't mean to rant :-)