Yes, a low score on Appearance will affect your total score under the KCBS system.
Low scores on Taste and Texture however have a much greater impact on total score due to the current weighting system... why put so much emphasis on Appearance? Given the choice of receiving a 9 on Appearance and an 8 on Taste versus an 8 on Appearance and 9 on Taste, I'll take the second option every time. I choose to focus on making it Taste good over making it Look good (not always succesfully however!)
i would agree, BUT you can make something look better in the box, but you can't change what the texture is and there is very little you can do to affect the taste at the end. Appearace is a much easier point to get. You don't always get that second option !!.. I remember i screwed up chicken really bad in a contest last year, and i took extra time to make sure those damn things looked perfect in the box.. Got 2nd with it... never, ever, underestimate the power of appearance. You've got to have great appearance skills as your ace in the hole, incase you screwed up something else.