if your not planing to slide a lot of rails keep them tuned like your race skis. They will ski better all mountain and help you keep control on icey landings. If you care a lot about rails dont tune them jsut let rail slidings natrual progression round the edges for ultimite slidage.
the first time he attempted the 450 his skis flew off because he had put his dins at 0 for the summer, and forgot to put them back up. he almost nailed his next 2 with din setting back in place