I am 5'9", 145 pounds. I ordered the 179's and they were wayyyyy too long for my taste in park skis. Of course I could ski them, but I want my park skis to be level with my height.
I sent them back, and got the 169's, and the shovel cups my forehead.
I went to Mount Snow this weekend and they tore it up, and they were a lot more stable than I could have imagined. I was unsure about the size at first, but after skiing them, I can say that they will not hold me back.