Learn to ski well slowly. Speed will come.
Speed hides a multitude of sins.
Absolutely. But when they enter that intermediate zone, want to move a bit faster but are still not ready/patient enough to finish the turn, not ready for the bite of short turning ski, SL skis can be a handful. Something 15-16 will be way more forgiving. As it was mentioned here, on SL skis the steeper the slope and the faster you move, things start happening very quickly, sometimes far too quickly.