Vantaggi
It looks great on your resume that you've worked at a big company like AT&T. It's almost impossible to get fired. If you do a bad enough job, you may get promoted to management. If you don't like your manager, it won't matter since you probably will only see him/her once a month. You get to work from home.
Svantaggi
"Everything is OK. Don't worry, you have no reason to worry about your job." Those were the words of the weekly meetings. Every week, without fail. Even as they start cutting people. Everyone is treated as a part of a formula. Actual formula they use for promotions: If you are making less than 80% of the AVERAGE person in your new position, you get a 5% raise. If you are making something like 95% to 98% of the AVERAGE you get 1% raise. And some other numbers in between. Doesn't matter if you are God's gift to AT&T or if you just barely are holding onto your job. Speaking of which, what do they do with people who aren't tech savvy (In a tech company, mind you)? Management! The teams I worked on seemed to be filled with people who were just waiting to retire. You won't see many people who are actually excited to be working there. No one willingly puts in the extra time because they thoroughly enjoy their job. Don't get me wrong, you'll find some teams that seem to be amazing. But I haven't worked in any of them, so I can't comment on them.