It seems to me like, assuming the quality of the teaching and student performance is at a high level for every band at the contest, which typically is for the "finals" round for many Area contests in the state, the groups that advance to State always have the better, more polished design.

Just an observation. Don't know really how this plays into educational value though I do think it's important to give kids a product that plays to their strengths (just like programming music in the spring can ultimately determine your group's success level).