Don't know how anyone else's service with them is,but around here,UPS is BAD for checking that a package has been signed for,when it has not!
My mom had a computer shipped UPS a while back.It never made it to her home,and after checking the UPS site,it showed that the package had been delivered to her house AND signed for.
It turned out that all the while,the package had been sitting on her next door neighbors porch(they were out of town,I guess)and the computer sat out in the weather,rain blowing in on it,etc,for three or four days!