Pros
I have worked at GS for 10 years, and the level of professionalism of my colleagues is the best part of working there. Generally very team-oriented, despite the high-caliber of self-motivated individuals that tend to work there. Excellent benefits, salary and bonus potential. Focus on the client and business principles are not just words on a page, the firm constantly reinforces them and demands them of each employee. Challenging work, good internal mobility for those who perform.
Cons
You are completely on your own in terms of career development and progression. Managers are not not expected to manage their people,nor are they rated in this area in their annual performance reviews. I was told straight out by a former manager that he was not rated on his ability to manage people who worked for him. 6 years under his management and I can confirm that is the case. Determine what you want your career path to be, then make it known broadly that's what you want. Your personal career development and success may not be a priority or even a concern of your direct supervisor. Don't assume working 70-80 hours per week will get you noticed or rewarded. You need to network and say 'No' often enough to force management to address resourcing issues or your career aspirations. Getting everything done no matter what simply enables them avoid addressing issues within their area of concern, and take credit for keeping things running smoothly. Managers at GS simply don't exist .... they are expected only to deliver towards the bottom-line, not to worry about the needs of their people. It's one way of doing things, and has certainly been successful, but be aware of this fact and act accordingly.