Everyone has this backwards...
TAKEN DIRECTLY FROM ARMADASKIS.COM:
Comp Base- (PIPE CLEANRS) A World Cup-inspired base that requires higher maintenance than the S7, the Comp Series
pays for the extra TLC it requires in one way: Speed.
S7 Base - Improved for 10/11, the new S7 features a gliding additive for increased speed and longevity. Our toughest base, find the S7 on any ski that’s looking for rails, ledges, and boxes as much as snow.
50 50 Base - As the name implies, the 50/50 is faster than the S7 and more rugged than the Comp Series.
AKA the COMP BASE is NOT meant for RAILS. It is meant for SPEED, has a soft base, and will get fucked on rails.