Vantaggi
Although it's not what it used to be before the company became so enormous, the culture here is generally very good. People are friendly, teams generally work well together and upper management works hard to reinforce the importance of collaboration and team spirit. Pays very well for Memphis--- it's so cheap to live here that you can buy a house on pretty much any salaried position. World HQ is a pretty campus next to a golf course with trees, a lake, a walking trail, big cafeteria overlooking the golf course, and a fitness center. Employees receive discounts on shipping and with certain companies like Dell and AT&T. Health benefits are competitive, there's a 401K, and there is still a lump-sum pension benefit as of 2014.
Svantaggi
FedEx is actually not just a single company--- it's a group of operating companies that "operate independently, compete collectively". Despite efforts to overcome it, there is still a tendency toward "silos" and being territorial at all levels. Having personnel headquarters in Memphis has become an increasing liability since it is a decaying city with a lot of crime, ineffective leadership, high property and sales tax rates, terrible traffic and failing public schools. The great majority of employees are here because they're either from here or they have ties here (family nearby, etc), they are careful about where they buy a home, and they are willing to fork over the money to send their kids to private schools. This could be a good place for a young, childless person, especially someone interested in the arts, to put in two or three years but overall, this is not a particularly innovative or nimble company; there's a lot of "this is how we've always done it".