Pros
I enjoyed working here. I felt supported by my team and I supported them whenever I could. It's getting more and more an international company with more people working there from different countries, although most people (of course) remain German - which is perfectly fine.
As an employee the secondary benefits are quite good.
Every month you got some money on your employee card to spend in the dome and/or Tropical Islands premises (to get yourself an ice cream, a new towel or something from the camp shop for example). Furthermore you could use the sporting facilities, sauna or swimming pools before or after working time. They also had their own "Betriebssport" which where classes given by professionals from outside the company in for example yoga.
A lot of things were well arranged within the company; although there is always room for improvement, hence the 4 stars.
Cons
As it's a big company it takes very much time to get things changed. Also some of the employees are stuck in a certain pattern which makes them reluctant to change some things. They remain to have the idea that "the old way is the best way" - which is not always the case.
Also the patterns in the top management of HR are quite rusty (HR management in the offices in the dome of TI). The people working here have been with the company over 10 years and this you notice. I believe some change in management would be good here. A new fresh look on the company and it's HR policies + hiring is needed.