Pros
-Incredible pay for what it is, with overtime at $18.75 (and since it was the Christmas season I worked overtime around 2-4 hours a day) -flexibility in choosing who you work with (I had a few different drivers and while I stuck with a main one, the opportunity is there) -for those in need of money and a thing to do, this will give you that thing to do--as a college student with the whole month of December free, I latched onto this and got a great deal of money from it. They will have you working practically every day if you desire.
Kontras
-On the other hand, they will have you work practically every weekday. If you're looking for something more part-time, I would not go with this. The latest I worked was 8pm (after starting around 10am) -For those in densely populated areas I'm sure the level of package delivery is even worse than what I had to deal with (live in a town of ~48K). In the week leading up to Christmas the packages were overflowing into the drivers area, and we had to deal with those and the ones right inside before we could even begin to move around in the back and organize packages. I imagine it's even worse in more highly populated areas