First off, I do a ton of walking at work, about 5-8 miles daily according to the pedometer.  I had been shredding through just about every name brand and off brand pair of Khakis out there.  These Carhartt Twills are the ONLY pair to not tear through in the thighs/crotch area.  They are heavy duty and stain resistant.  They are a bit stiff at first but that subsides after a few wears/washes.  Ive been wearing these daily for over a year and just now purchased a few more pairs because my waist grew. :) If you are having problems wearing through pants then these are the ones for you.