Jaca

The only problem with money orders is that they can be extremely difficult to track down in the case of a nonfulfilled internet purchase. While there is a system in place to locate them, it can take 6 to 8 weeks for the company who funded it to follow this process.

Most cases of dispute must be presented within roughly 60 days (not specifically sure about Ebays T&C), which is beyond the dispute period of some cases for which you would have to show proof of non-receipt of the money order.

Of course, this is important in the case of the buyer. I've personally never had a problem getting immediate cash for money orders cashed at my bank, or the US post office).