I work at a demo center in the Catskill region of new york and I find that lighter skiers prefer the 163cm. For example, a 155 pound man advanced/expert skier tried both the 170 and the 163. He first wanted to try the 170, but I recommended he try the 163. First he tried the 170, then he came back and switched to the 163. He liked the 163 better. It really goes more by weight than height, although height also plays a roll. I am 5'5", 140lbs, female, 21 years old, advanced, and I love the 163 (they don't make it any smaller). I think it is a little long for me, but I like it better than the aurora 156cm (women's version of the ac50 - same dimensions, but a little softer). if you are skiing out west, you can go a little longer, but if you are skiing mostly on piste, go on the shorter side if you are light. The AC50 is one of my favorite skis, and I have skied about 20 different pairs of advanced/expert level skis this year (if we had more skis, I would have skied more).

Being an aggressive skier, the 177 sounds perfect.I aggree with this assessment! I'm 5'7" 160lbs and have the 177. While some say I could have gone with the 170, the 177 are much better at the mach speed they like to rip at! If you ski fast, definitely the 177's. If speed isn't your game, the AC50 probably isn't either....