OK, here goes ...
Chicken: 8 pieces are always good, but the sizes don't match & the shapes are uneven - try trimming them down so that the size / shape are equal. The color seems to be un-even but that might just be the sauce. Also, I think that you need to raise the meat up in the box. Either more parsley or some chopped lettuce under there would help.
Ribs: The ribs themselves look very good. Try putting 5 in a straight line instead of staggering the bones then one on each side, it will look more uniform that way. Again, raise the meat up, it makes a better looking box.
Pork: As far as the meat goes it looks good to me. It looks like there are only 5 slices & 5 chunks in the box. Although that would be legal for a KCBS comp I would advise putting 6 pieces of each type in the box. Again - raise it up.
Brisket: Your knife skills look good - the slices are cut clean & even. I would have cut off or trimmed the heavy bark on the right side, or better yet, tried to find a few more of the larger pieces and cut them down to fit - more uniform that way. Also I think that the burnt ends need to be out there front & center, not half hidden. Here again, the sauce looks un-even.
I'm not trying to be overly harsh on my comments, I'm just trying to see what would help in your next comp. It looks like you've got the basics down good - now all that's left is the fine tuning. Unfortunately, some judges really get picky on the apperance scores.