First off, let me say that I just took my CBJ class and have no actual experience. Take what I say with a grain of salt...
I found it very confusing on how to judge based on one CBJ class. I am in no way saying my instruction was inadequate, just that the KCBS doesn't exactly do a good job telling you what the scoring system is supposed to mean. I understand that the CBJ is a ticket to a judging apprenticeship where you learn the finer details from the other experienced judges at comps.
As a future competitor, I learned from the class that garnish is for more than good looks. It keeps the meat from sitting in a puddle of juices and sauce and keeps it from sliding around the box. Thus the final product will be better packaged before serving.
I don't think garnish should affect scores, but hundreds of cook teams know that presentation will have a subtle effect on the perception of your product. I think the KCBS does then "require" garnish by default.
William Conway - Big Steel Keg, Bubba Keg Convection Grill.
NASA uses [COLOR=Red]RED[/COLOR] Thermapens. Just sayin'