Toregar

Definitive differences there in your pics mate. My chest is the hardest bodypart for me to develop. I started DC training, and by sheer accident, I discovered my chest is composed of more slow-twitch fibers, rather than fast-twitch A or B.

Slow-Twitch fibers are your aerobic (Think prolonged activity) fibers. They're highly resistant to fatigue. Long distance runners and whatnot, have a lot of slow-twitch fibers in their physiques.

Fast-Twitch A fibers are anaerobic (Think more along the lines of explosive activities) fibers. These fibers are more susceptible to fatigue. They are for more prolonged anaerobic activities, such as sprinting.

Fast-Twitch B fibers are anaerobic fibers. These guys are the most susceptible to fatigue. They are used for very short anaerobic activities, like weightlifting. Your big powerlifters use a lot of these fibers.

So, since I found I was more slow-twitch, I upped my reps a bit from 6-10, to 8-16. My chest has never responded so well. The entire training style change, from DC, probably has something to do with it as well :P

In the end, you want to exercise your bodyparts through all rep ranges. I still do 6 rep bench presses, to keep my strength up. I just do more of the higher rep work, because my chest better responds from it. Once I hit 16 reps with a given weight, I knock the weight up 5-10 lbs, and bang on it till I get to 16 reps. Repeat, over and over. It's all about progression, anyways :P

Anyways, you have a good frame on ya mate. Fill out nice with the proper amount of muscle, fer sure.