Pros
The people I worked with in Nashville were great. I was there for 10 years and for the most part my co-workers were like family. The best thing about that job was the people I worked directly with. Local management was good about arranging a flexible work schedule. That may have changed since I left, and then changed back after a few changes in management since then.
Cons
Most execs and upper management are out of touch with he front line workers. They often manage with fear tactics. There was always a layoff looming. I was fortunate to never get let go in any of them, but it was always in the back of my mind. Pay was mediocre for some, but if you really want to get ahead it isn't going to happen at XO unless you get lucky. Hard work plays into it as well, but moving up isn't totally dependent on doing a good job here, at least from my experience. The job itself doesn't really give you the sense that you are doing anything worthwhile in life. You are there to make a paycheck get your numbers and come back the next day to do it over again.