Avantages
There aren't any pro aspects to working at Xerox, if you're utterly desperate for a job (and you would have to be to consider it), then maybe working for Xerox would tide you over for a few weeks. My advice would be to take their training and leave immediately.
Inconvénients
Xerox is everything you are hoping to avoid particularly if you are thinking of being one of their field engineers. You'll find the lowest salaries coupled with the highest workload. Xerox has (or had in the past), a BS award for their service levels, but you'll find that the service they pretend to offer doesn't actually happen, if you as an engineer actually delivered these service levels the management would be all over you criticising the amount of money you spent and the slowness of your work. NO ONE NEEDS THIS.