Can't think of any. You can get better compensation, more interesting work elsewhere, whether it's Warsaw or any other big town. Comarch is a very bad choice for a career start or for experienced programmers and IT professionals.
Cons
Can't really think of any reason to work there. Very low compensation, lack of respect for candidates and employees. Comarch treats developers and software engineers as cost, paying really low compensation and not offering much learning experience/job satisfaction.