CGI is a good place to start at but not a good place to stay. If you are looking for advancement go somewhere else after max 2 years. Pay is terrible, raises very small.
When I worked at the CGI office, if I turned to talk with someone about anything not work related the team lead would put a quick stop to it (sorry but should be able to talk to fellow employees). The worked me like a dog, no down time allowed
When I work at client site it is much better atmosphere as you get to live that company culture. Still no matter how much the client likes you it is not reflected in your yearly reviews. (the reviews have no impact on your income)
Management treats employees like dogs