Pros
I've heard that of the major mobile communications companies in the area, T-Mobile is a bit less totalitarian. However, that's not to say that it's a company of freewheelers. As a smaller company than others, the opportunity to grow and climb the management ladder is exceptional. Benefits. Period. It's part of the reason - major part, actually - why I took a job at T-Mobile. Quarterly bonuses, too. These were things unheard of at other companies I've worked for. Employee phone plan. With mobile communication so critical these days, have the company subsidize your phone and plan, and the phones of your family, to a degree, really help.
Cons
Lack of direction as a whole company. Of the three major groups, none of them appear to talk to each other. Perhaps there is talk going on above the rank-and-file, but it's not very clear. A results only oriented philosophy at the expense of people and expertise. Processes will only get you so far; you need people to abide by and support the processes for success. Too often a new process is introduced that conflicts with existing processes and it's up to the people to make it work. Had people been brought into the design of the process, a couple of things could have been eliminated and streamlined.