I went through a two month run-around with the USPO over a Wilton vise they lost. They admitted they lost it, but the insurance turned out to be worth zip. They won't accept e-mail as a valid form of documentation (guess the PO doesn't like email), always had another form they wanted filled out, documentaion was never acceptable, blah blah blah. All this over a $75 claim.
Became obvious I was being "bureaucratted" to death, and I gave up, which was surely their goal. Wasn't worth the time; I refunded the customer personally to protect my reputation, and promptly made it a point to avoid them at all cost in the future. Will NEVER ship anything in a box through them again, and set up all my bills on the computer that I had been paying through the mail.
So, in my opinion, postal insurance is worthless. YMMV, I hope so.
Greglea, thanks for taking the time with your explanations. Please don't take the above statements as a personal attack or flaming your previous posts. This is simply my viewpoint on the matter, and my experience with the topic at hand. I wish this on nobody; maybe others have better luck.
Rob