The thing that I would like to add is that shaped skis strip you of turningabilities that you can exploit and/or develop. If you like to make the same basic turns every run or run gates I guess this could be good.
As stated above it depends on location. Whether I'm skiing in Colorado or Michigan, I want a stiff, straight edged ski so I can carve as I desire not what the factory has determined with the hourglass shape that they chose. Free skiing should in fact feel free not restricted.