The most recent Silverfish build off required incorporating multiple elements, a minimum of two from the following list: concave, camber, flex, rocker, and kick tail.
Rather than go for as much as I could cram into a single deck, I opted instead to just go with a nice clean concave and camber deck.
The board also has flex, but not enough to claim it as a feature. The bigger thing I was going for was to use Original trucks on a long wheelbase deck without risers.
I also really wanted a drag hole, it's by far the best way to tote your board back up a hill in my opinion.
My last requirement was that the deck be freestanding, not for function so much as the fact that it just looks cool. I'm a big fan of "looks cool".