Pros
DT is without doubt still one of the best employers in the telecommunication industry. As a German company with a strong Workers council and a large Union presence, the regulated collected agreements provide an excellent base for people who work there. DT is a company that truly cares about their workforce and are willing to invest in them long-term. Most of the people who are working at DT stay at DT for a very long time and there is a reason for it.
Cons
The company is still undergoing a transformation from a state run enterprise that has a telecommunication monopoly to a capitalistic profit oriented competitor in the marginialized telco market. While this certainly holds a lot of opportunities, a lot of things that were very traditional for DT are already lost. DT was a technologically driven company in the past, that was able to develop their own telecommunication standards, equipment and systems, while today it has been mostly reduced to the traditional service provider role. Since privatization of the company, marketing people have had a very strong say in the companies' strategic decisions, and for a technologically driven company this is naturally not very good news.