keep in mind that skis loosen up after a bit of use, but a big difference with flexes will stay. Then again, if you're still growing, it may be a good investment. Also, if you like to ski fast, a sturdier ski will suit you better. You might be surprised how you can butter a stiffer ski with the right technique.
Then again, its all you're choice and you can have fun on a pair of noodles too
I know a rider 5'7" 130 lbs on AR6 166cm 2007. Works great. There are always stories of they made it stiffer or softer so I do not know what yr ur ski is...
U may have to grow into the ski or combined with a backpack and boots etc.... they ski may be great for next year. But u may get good pop this year. I don't think it's too much of a mis-match-up for this yr.
By Xmas if u eat enough turkey it will be great.