Despite the listed pros, my stay at Sigma proved to be a mixed bag eventually. Not primarily because of the low salaries and benefits (that's a given in most consultancy companies in Hungary), but rather because of the management incompetence I experienced in the latter half of my stay there.
The projects I was assigned to were constantly characterized by unpredictable workload, coupled with erratic customer requests and deadlines that were impossible to meet without working overtime in a regular fashion. Although they promised to handle this, management never actually put a stop to the impossible customer expectations, and never addressed them in any substantive way, even when communication with customers turned very tense. I felt that to them, it was much more important to keep the project contract and spoon-feed the customer than support the worn-down employees doing the work itself. This, of course, resulted in a turnover rate in the project that highly exceeded any other within the company.
The working conditions therefore strongly depend on the conditions within the customer project you are assigned to. If you happen to end up in a well-managed one, you are in for a good time. If not, you are on your own.