Pros
There is an opportunity to make a decent salary and it is a decent place to start a career. Due to the sheer size of AT&T there is an opportunity to learn many different asspects of Telecomunications and General Business.
Cons
AT&T has poor management and entirely too many executives. Due to the emense bureaucratic structure a great deal of time is spent in justifying the job or jobs that you intend to do instead of just accomplishing them. If you are a first line manager there is a good chance that you will be given unionized labor. The problem here is the corporate culture has lead to an us vs. them thought process on both sides. This is another source of frustration. HR has been converted to a mostly computer based system and benifits are reduced yearly. Receiving a promotion is very dificult.