Pros
Fun environment. Lots of parties and lots of freebies. You get christmas gifts every year. There is free lunch in somewhere in the building at least once a week. It is almost impossible to be fired even with unethical behavior. There is one quota for sick leave and vacation which adds up to be 24 days a year. Health benefits are competitive with other companies. Convenient location. There is Free parking. There are good restaurants in walking distance.
Cons
Salary is low. There is a huge difference in salary between the employees who are doing the same job with the same position. T-mobile has values but nobody cares about the values. Management is political. Unethical behavior is OK as long as you are a manager. Some people get promotions one after another because they know the right person. There are quarterly evaluations. Therefore you have to evaluate yourself every 3 months and it is time consuming. FMLA leave is not competitive.