Replying to ARV vs. MSP

ok, so i'm looking for a new fat ski, mostly for skiing pow, choppy snow, slush, both in colorado and new zealand. i'm 5'3 and i'm tossing up between the 170 msp and 175 arv. here are the pros and cons of each for me:

msp:
pros - good size, stiff, have heard lots of good stuff about them
cons - very small sidecut, unknown turning abilities which i won't be able to demo before i buy

arv:
pros - had ar5's and loved them so i know armada is the goods, more sidecut than msp, wider waist than msp
cons - 175 might be too much ski for me, since i've been on 160's for the last 2 seasons. i know i can handle 170's but not sure about the jump up. strength-wise there won't be a prob. but the problem is excess speed. i have trouble keeping my speed under control as it is with a 160.

i would appreciate any input/comment on these skis, cheers!