I have probably bought 50+ shirts at PYE in the last several years, and have used about 20 of the Cathay coupons to get $500 off of each. However, depending on the price of the shirt my 15% discount at the store gave a greater dollar off than the $500 cert (you can use either offer, but not both). I have also redeemed half a dozen of these coupons for the free handkerchiefs, and I find these to be of good quality as well.
So, in sum, I have found the Cathay PYE coupons to be of good value to me. I'm still holding onto six coupons, and am just waiting for the spring release of the new fabrics at the store; then, I'll order some new shirts.