I shipped something with UPS. It never got delivered. When I contacted them, they keep saying it was delivered. There was no proof of signature and the person this was delivered to was not the recipient. My package was going to the Caribbean, they delivered it to Georgia, USA. They didn't even make any effort to relocate the package. They were reluctant to even start an investigation when I reported that it was not delivered. It too me a week of numerous phone calls and emails to get them to reply saying, the package was lost/damaged.
I would say it's a horrible, costly service and one should AVOID this.