Vantaggi
Depends on which side of Xerox ... Real Xerox, or ACS pretending to be Xerox. On the Real Xerox side you will have a better holiday schedule, no furloughs (no weeks off without pay), management that typically cares to hear your opinion and help, good working relationships with peers.
Svantaggi
On the ACS pretending to be Xerox side (they will tell you "We are Xerox services" and "We are all one company" ... lies) you can expect to have a single focus: finding your next job. Their sole focus is on reducing cost, typically by moving jobs overseas or sometimes simple elimination. You can expect to work 60 hours a week with no "thank yous", and when management screws up, which is the normal mode of operations, you will get to experience a week off without pay. Expect to be working side by side with a Real Xerox person in the next cube who has better salary for the same work, better holidays, better vacation, better 401K benefits, and a better health plan.