Amazing finish quality. What made the original turners work was the monocoque construction.. ie what we call "cap" construction. Cap Skis- don't do it as well as Bob Turner did because they have to have flat tops for mounting bindings... and lose rigidity and snap as a result.
It is the curve that gives the material it's rigidity and flex characteristics.. and as the height of the cap approaches the width of the material the torsional rigidity goes up... not down.. so an extra wrap of material around the skinny nose can yield the same longitudinal flex by way more nose rigidity..and the higher the arc of the nose... well. you get the same result.. (too high is unstable though- just a little is needed) .
For instance... take a sheet of fiberglass- and let it cure flat in the same plys - and glue ti to make it a bi layer of multiple plys..
.. now take a duplicate sheet and amount of material and let it cure in a cereal bowl and then glue the flat sheet to the bottom... it will resist twisting intensely..
So that 3d curve gave the Old Turners the needed wheel clearance without sacrificing much torsional rigidity in the nose an tail sections...
It was also the reason why the Turner Hybrids (A crappy construction made the same way as the lowest cost snowboards by Taylor Dykema
http://www.tauberaronsinc.com/taylor/taylor1.html cut by water jets to be cheap.. ) which had no top curve across the deck or down the rails were a not as successful in flex patterns in the same shapes as the original Turners (the nose and tail would "bog"). The shape of the Turner Hybrids no longer could be optimized because the construction was changed to one that did not benefit from the shape (in fact that construction just wasn't suited to racing) . heck...no one ever listened to me

.. and Bob never liked those decks either....he wasn't exactly sure how the shapes translated into performance.. but he was hell of a shaper and a perfectionist, and very very into improving his designs, the racers just knew which ones worked, and he listened to what we wanted... and if the communication between the racers was really good- he made world beaters.
Carbon fiber is torsionally more rigid- so in theory.. the boards if made of the same shape as the original fiberglass Turners...they would need/take advantage of smoother pavement.. they would be less road surface compliant- but more responsive and super super snappy for high CPS.