they are a 70% park 30% big mountain so they are a bit stiffer, so you can boost a bit higher in the park. VERY GOOD WARRENTY, sidewalls tend to chip alot, because of the design but that does nothing to the performance. the sizes are a bit different, like the 169 is a 172 or something and the 179 is like a 182. very sick ski, and the mounting cm thing on the side makes it easy to make a decision. mount at 4cm or 3 1/2 for more of a park rider, and a bit farther back if you arent. i've heard that youcan mount them 4 1/2 to five cm forward, but then your all-mountain perforce will lack. depends what you ride.