I dunno dude, with the Hellbents, the sizes actually measure to about 175 and 185. My friends 179 Hellbents are as long as my 185 Chopsticks, and they are both rockered skis. So if your trying to decide between 169 and 179, you might wanna go with the 169, cuz its actually 175 or 176.
I would be skiing a 179, and I am 5'-9" and 170 pounds. I think you will either love or hate them with whatever you get though. I personally find them too noodly.