Just a quick example of the US Postal Service - this came in yesterday:
At least both halves showed up, taped back together, and in a little plastic aploogy sleeve. The gasket inside being returned was, well, NOT inside. No recourse. Sure, we get damaged packages thru UPS, but at least with UPS the parts are insured and we KNOW that a claim gets somewhere. The claims process thru USPS is simply useless as we've tried on several occasions.
EricB