The Other Side of the Contest Table: Judging

I don't have any big projects in the pipeline, so I wasn't a contender at the Autorama contest this year.  I volunteered for judging duty, and it was a real eye opener.  I thought that judging was simply a matter of establishing some criteria for quality  and applying it to all the models in a class and pick the best one.  Simple right?  Wrong.  Our judging team did our best to consistently apply many different criteria to the entries, but the problem is that each model will have strengths and weaknesses.  One has great paint, but poor chassis detail.  One has a realistic engine compartment but the front wheels are toe'ed out.  How do you judge a shiny custom paint job against a realistically weathered beater?  In the end, we tried to reward craftsmanship, creativity, and knowledge in multiple aspects of the model, but it's not easy.