I've only had issues with the USPS shipping what was then Parcel Post. I shipped an old no-name 70s guitar amp that was lost and never recovered. I had purchased USPS insurance on it and had proof of the insurance, but the USPS would not honor the insurance because I couldn't produce a company catalog, company price list or an advertisement from back in the day. They said I had to have original material showing a picture of the amp and the original price. The small company was long out of business and there was nothing on the internet about the business.
I had sold it on eBay and had my own pictures and proof of the auction and payment via PayPal but it didn't make any difference, they still wouldn't pay the insured amount ($150). They treated it like an uninsured item and $50 was the maximum they would pay. I eventually just dropped efforts to get compensated and moved on..
I will say I've shipped a lot of items First Class and Priority Mail without a single issue, so no complaints on USPS service generally. I don't ship much now, but if I have an oddball vintage item I make sure I use Fedex or UPS.
Last edited by steve f; 05/08/15 02:07 PM.