I've been using 175s since I've been mtn biking about 6 years.
I'm 5'6" and just picked up a 170 crankset. I know it's about 3 % less torque, leverage but does it really make a difference? I always seem to bash the 175's. I figured I can live without the 3% leverage and make up for it in the gears.
Mtbr's 2016 Winter Biking GearReviews and Roundups
Results 1 to 2 of 2
Thread: 170mm vs 175mm cranks