The USDA lowered their recommendation a few years ago to 145F, for all but ground pork. Unfortunately, most people aren't aware of this, so they continue to cook pork until it's seriously overcooked. When cooked properly, a chop should still be a little pink, not gray.
Personally, I cook to about 140. Trichonosis is all killed off by cooking to 136-138 for just a couple minutes, or at 140 for a minute. Anything beyond that is just drying out your chop.