Upload & Sell: On
I have never had any problems with eBay, other than once winning an auction for an incredible low amount on a no reserve auction and the seller refusing to ship it (or take my money for that matter).
I certainly would not buy or bid on anything that did not include the "eBay buyer protection" though.
While I have never had a need to use it, I guess I sort of take it for granted that along with proof, they will honor the guarantee.
One practice that I do follow is that when I am selling something, I photograph the packaging process for my records. When I am buying, I actually video tape the package opening process on any items costing a lot (or fair) amount of money.